


Shameless

by KonstantineXIII



Category: Kill la Kill
Genre: Anal Sex, Because who does that?, Condoms, Dirty Talk, Double Futa, F/F, Futanari, G!P, G!p Ryuuko, G!p Satsuki, GP, Girl Penis, How Do I Tag, Incest, Loss of Virginity, Masturbation, Me. I do that. Because I'm a sicko., Mild Kink, Mutual Masturbation, Oral Sex, Relationship(s), Sex, Sibling Incest, Sweet, Top Satsuki
Language: English
Status: In-Progress
Published: 2016-04-18
Updated: 2016-08-06
Packaged: 2018-06-03 03:02:05
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 27,200
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6594040
Author URL: https://archiveofourown.org/users/KonstantineXIII/pseuds/KonstantineXIII
Summary: <blockquote class="userstuff">
              <p>The absolutely shameless story of two sisters who might love each other just a little too much. Futa/Incest/Sarcasm The plot is almost nonexistent.</p>
<p>Also published on FF.net. I just thought you guys might be a little bit more twisted over here.</p>
            </blockquote>





	1. Chapter 1

Fuck.

This was the third set of sheets this week I had woken up to find ruined. The third time this week, and it was Wednesday. Fuck. I glared at the ceiling and felt the stiffness of drying cum in my underwear and on my sheets. 

I sighed deeply and got up. I stripped the bed and myself and balled it all up. I showered and dressed in my school uniform, making it downstairs in time to have my sister send me a disapproving look as I sat at the kitchen table. 

“Bacon?” I raised an eyebrow. “Since when did you discover the west, Sats?”

My sister put the dirty dish in the sink and sat at her tea with a roll of her eyes, a smile twitching her mouth. 

“Since I got sick of throwing out the natto you don’t eat every other morning,” she deadpanned. 

I inhaled hot coffee and coughed, perfectly lady-like. Satsuki smirked at me, her stormy blue eyes dancing. Her fingers twirled a pen and she let me choke in peace, thinking of something to write down. 

Watching her nimble fingers reminded me of the dream I had last night, and I scowled, thinking of the aftermath of that particular dream. My scowl lasted well into breakfast, and delightfully extended to the car ride to school. Satsuki apparently could tell I wasn’t in the mood this morning, because she let my funk continue without interruption, only telling me to have a good day at school and to keep my phone on.

‘Stay awake’

Wow, maybe I might turn my phone off after all. 

‘Bite me.’ I replied to her.

‘Don’t text in class.’

I growled at her hypocrisy. 

Satsuki, only a year older than my freshman self, was already on the student council, and everyone thought she was shoeing for president next year. Personally, I sincerely hoped not. Sats already walked around like she had the biggest dick on campus, with an even larger pole shoved up her ass. At school, my sister was a walking bundle of nerves. 

School was boring as hell, made more bearable by my best friend Mako. But even then, the day let out eventually. The ride home was even quieter than this morning, but this time it was Satsuki’s fault. I tapped my fingers against my leg and tried to figure out what might have come up. 

The radio fizzled and played shitty pop songs, and I fiddled with it enough for Satsuki to break out of her thoughts to tell me to knock it off. We got back home before I had a hypothesis, so I let it go. 

A few hours later, Sats knocked on my door softly and asked if I was busy. 

“Nah,” I shrugged, gesturing to my game system across from my bed. She nodded her dark head, grimace in place. “What’s up?” I asked. 

“Room for a party of one?” she tried, cracking a smile.

I laughed and patted the space on the bed next to me. 

“Right this way, ma’am,” I grinned, pausing my game and making a silly, grand gesture. My sister and I were fucking dorks when we were alone, a trade secret that we both would take to the grave. 

Satsuki stretched out on my bed, relaxing, and I unpaused my game. I had changed out of my uniform into a tank and sweats, and Sats had donned a soft cotton tshirt and running shorts. 

“Fucker,” I murmured acidly to the screen. Satsuki laughed at me.

“Ryuuko, three o clock!” she shouted. I quickly took the camper out and laughed manically. She helped me kill some baddies for a while, and the feel of the room helped us both unwind. After my team had won the game, I muted the menu screen and looked at my sister expectantly.

“So what’s wrong?” I asked bluntly. Satsuki raised an eyebrow and dodged neatly. 

“Nothing,”

“Wow, that was smooth, Sis.” I ground out, unimpressed. She smiles at me charmingly. 

“Why haven’t you put new sheets on your bed?” she challenges, and I know I just lost the game. My face instantly flamed, and I looked away from her. 

“I did,” I mumble. 

“Are they invisible sheets?”

I grimace and came clean… so to speak. 

“I had to take them off again,” 

A pause, and then it clicks.

“Oh, Ryuuko,” Satsuki groaned lightly, a hand to her face. 

“I can’t help it!” I explode self-consciously. 

“This is the third time!” 

“I know that!” I threw myself backwards to lie down next to Satsuki, covering my face with my hands. She let me wallow in my mortification. I groaned and looked at her. 

“Don’t you do it?”

She pursed her lips, her blue eyes drilling into me meaningfully. 

“I used to,” 

I paused. 

“Okay, how’d you make it stop?” 

Satsuki raised and eyebrow and make a vague hand gesture. I frowned. 

“I don’t speak sign language, crazy.” 

“I masturbate, Ryuuko.”

“Oh…. Oh.” 

Satsuki sighed deeply and I saw out of the corner of my eye that her cheeks were a little flushed. I cleared my throat. 

“I mean, it’s not like, ya know, I don’t,” I started self consciously, “But… uh,” My courage failed and I stopped. Satsuki turned her black hair to look at me. 

“But what?”

I kept staring at the ceiling. This was humiliating. 

“Nothing,” I grunted. 

My sister poked me. 

“Hey, it’s fine. Just tell me,” she prods gently, her eyes soft and caring. 

I grimace. 

“You’re not allowed to make fun of me.” 

“I wouldn’t.”

“You would.”

“I’m not Nonon, Ryuuko.” 

“Well, that’s because Nonon is a fucking bitch,” 

“Ryuuko.”

“Okay, okay!” I huff. Here goes my dignity. “I.. ItrytodoitbutIcantcome.”

Satsuki pauses, “I don’t speak gibberish, crazy.” She teases me back. I huff loudly. 

“I try to masturbate, but I can’t come!” I shout, my face on fire. My sister is quiet for a long moment after that, and I have to see if she’s silently laughing at me or not. 

Satsuki looks deep in thought, on the contrary. Relief fills my heart. 

“Ever?” Is all she asks, and I love my sister for not making me feel like a freak for this. 

“No, I have before,” I tell her. The Call of Duty screen plays over silently in the background. 

“Do you remember what you were thinking about when you did?”

“Uh, yeah…” 

Shit.

“What was it?”

“I’m not fucking telling you that!”

Because it was you. Yeah, I had accidentally masturbated and gotten off to mental pictures of my full-blood related older sister. I’m pretty fucked up. 

“Okay, okay, relax, Ryuuko.” She calmed out. I breathed, losing more dignity by the millisecond. “Are you sure you’re… doing it right?”

“How do you fuck that up?” I burst out, grumpy. 

“I don’t know!” Satsuki argues, “I just want to make sure!”

“You wanna know so bad?”

“I’m just trying to see or not!” She replied, stagnant.

“You want to see?” I argue, heated. 

“Sure.” Satsuki glares. 

I pause. 

“Wait, what?” 

“Show me,” she says easily, relaxing into my pillows once more. 

“Seriously?” I reply. My heartbeat starts to pick up. Is this real? My sister shrugs at me. 

“If you want to,” 

Instantly, I’m horny. It’s not something I can help. But all the blood in my body starts to circulate through my crotch, and I can’t look away from Satsuki’s piercing gaze. My mouth dries out, and all the liquid transfers down south. 

My hand twitches, and I feel myself reach for my junk. 

“O-okay,” I rasp out. Satsuki smiles, totally calm. “I dunno, Sats- I feel kind weird,” I tell her, my fingers brushing the growing tent in my sweats. “Just doing it myself.” I look at her, then, and swallow for luck. “You could join me?” 

She doesn’t look away from me, but the smile on her face dims a little. She swallows, too, and nods lightly. 

Holy fuck, this is happening. 

I nod, turn my table light on, and get up to turn my overhead light off. The room gains a little ambiance, and I shut and lock my door. Our father was out of town, and would be for another week, but it felt right. 

When I look back to my sister, she’s shimmied out of her shorts, and is cupping her crotch. I swallow, my eyes lingering over her hands. She raises an eyebrow and I smile a little. 

“Come on, Ryuuko,” she whispers out evenly, and I feel myself relaxing ever so slightly. I tug on my sweatpants gingerly, before just breathing deeply and stripping them off entirely. 

“Wow,” Satsuki says, her eyes studying my semi-solid penis. I shifted from foot to foot. 

“What?”

She smiles at me. 

“You’re very thick,” 

I laugh and practically feel my ego swelling. Oh, wait. No, that’s just my dick. Satsuki laughs lightly, and lets her hands fall away as I get closer to her. My mouth drops. 

My sister is large. Probably eight solid inches, and her dick puts my six inches to shame. Well, sort of. She was right; I am thick. I can’t wrap my middle and thumb fingers around my dick and touch. But Satsuki’s hung like a horse, and her dick is gorgeous.

But I keep that thought to myself. God, it was disturbing how attractive I found Satsuki. She’s also fully erect, and I grinned a little. My sister was turned on. Which was an awesome sign for me. I joined her on the bed, and laughed. 

“So, this totally isn’t weird, right?” I smirked. 

“Of course not,” she replied sarcastically. “So, show me.” 

“God, is it all business with you?” I complained. She grinned at me. 

“Actually, I’d call this pleasure.” 

I scoffed. “I can’t believe you just went there.” And I reached for my dick. I knew what kind of pressure I liked, so I got right down to it. I massaged my tip, and the underside, and sort of supported my shaft with my other hand. I shut my eyes and tried to zone out. 

“No.”

My eyes snapped open, and I looked at my sister. She was fucking masturbating! I mean, I know I was too, but I just – shit, I was hard. 

“No?” I restated, borderline irritated. 

“No.” She confirmed, always in the right. I frowned at her pushiness. “Look what I’m doing, Ryuuko.” She ordered me. Her tone set my teeth on edge. 

“That’s exactly what I’m doing!” 

She scoffed.

“No, it’s not.” 

“Yeah it is!”

“If you were doing this, you’d be coming, little sister.”

Her reminder at the fact that she was my older sister sent a flame of arousal into my lower stomach, and my dick tightened even further. 

“You think you know what could get me off?” I challenged.

“Of course,” she sneered at me.

“Then do it!” I dismissed. 

“I-“ She hesitated. “What?”

I swallowed. Shit. Too late now. I just… I wanted so badly to touch her. For her to touch me. Satsuki..

“If you think you’re so good, get me off.” 

Satsuki propped herself up on the bed slowly, her blue eyes boring into mine, and I let her see whatever it is she wanted to see. Then, I felt a warm, warm hand grip the shaft of my dick and slowly pull. 

“Okay, Ryuuko,” she said softly. I swallowed, and watched as my graceful older sister shifted to lie on her stomach between my legs so she could have both hands free. She leaned over, and at first I thought she was actually going to put my dick in her mouth, but she instead let a trail of spit spill from her lips onto the head of my dick.

I almost came right then. 

Then, she took one hand and spread her palm over the tip, and soon my precum had made it slick as hell. Her shoulders muscles flexed as she jerked me off, and it was so incredibly sexy. Satsuki’s other had joined in, and she multitasked, one pumping my shaft, the other massaging the head of my cock. 

I had forgotten to stifle the moans ripping their way out of my chest. Satsuki had been right. I was going to come. My breaths were starting to labor, and she didn’t look away from my face, her hand pumping steadily. She started to gain speed and twisted her wrist expertly; a kind of corkscrew turning that sent my brain on shutdown.

I stared into her blue eyes, and there was something I needed. Something right in reach, and if I got it, I’d be done. What the fuck was it? God, I needed to come so badly. 

“Sat- Satsuki?” I groaned out, and my sister smirked at me. 

“Yes, Imouto?” she purred. That was it! 

“Holy fuck, keep talking,” I practically shouted. “God, I’m so close,” 

Satsuki’s low voice seemingly reached my ears and dick simultaneously,

“Ryuuko, I’ve got to come clean… I’ve been thinking of being with you like this for a long time, now,” her voice was the gorgeous contralto I listened to while she was singing in the shower, and thinking of her wet and naked.. 

“I’m sorry, Imouto. I don’t mean to take advantage of you-”

I came. 

Satsuki’s hand was covered in semen as I finished jerking into it, and I panted hard, looking at her alertly. Her words finally caught up with me.

“Really?” I blurted out. 

Satsuki chided me. 

“You’re really supposed to say when you’re about to come,” she responded crisply. I rolled my eyes at her. 

“Satsuki,” I said clearly. “Did you mean that?” I stared at her intensely, looking between each of her eyes. The same irises I had. My full-blooded sister. 

“Yes,” that sister whispered. “I know it’s wrong,” she said, trying and failing to look away from my no doubt piercing gaze. “But I can’t seem to stop thinking about it. I understand if you don’t-“

“Fuck me,” I hushed out. 

“Pardon?” 

I swallowed, looking into my sister’s stunned and beautiful face. 

“You’re my sister, Sats, and I- I think about you like that too, sometimes.” I looked away from her. I still had a raging boner, and the picture was really odd. “I can’t help it. I have wet dreams about you, and- this is literally a dream come true,” I rolled my eyes when she smirked at the double entendre. 

“So…” I looked at her. “I want you to fuck me.” My face burned and burned and burned. “Please,” 

“Ryuuko,” Satsuki said softly, gently. I swallowed, not looking at her. “Okay,” she replied. 

I fixed her with a serious look. 

“Really?”

“Yes.” 

I gaped at her, my brain short-circuiting. 

“Do you have a condom?” Is what my brilliant mind came up with. Satsuki laughed, and I cracked a smile at the broken tension. 

“Yes,” she said easily. “Wait here,” and she left my room. 

I flopped on the bed. 

Holy shit. 

HOLY SHIT. 

Holy. Shit.

I’m going to have sex with my sister. My unbelievably hot, perfect, hung, sister. My stomach tumbled in a tumultuous firework of emotions. I was relieved to figure out that most of them were from excitement. Satsuki was my sister, my most important person. 

Wait, why does Satsuki have condoms?

My sister re-entered my room and shut the door. I glared at her and she looked curious. 

“What have I done?” she blanded out. 

“Why the fuck do you have condoms?” I asked angrily. 

She laughed at me. 

“Relax, little sister, they were a gag gift from my friends. Their little way of saying they accepted my ‘abnormality’.” 

I growled. 

“Nonon probably just wants in your pants.”

Satsuki smirked and I scowled.

“Why do I like you again?” 

My sister laughed aloud. 

“Because I can make you come?”

“Oh yeah,” I replied, smiling. We both chuckled, and then the moment of truth was upon us. I looked at Satsuki, and she looked back at me gently. 

“Ryuuko,” she started, climbing onto the bed. I sat up slightly. She reached out to cup my face, and my cheeks heated, “Will this be your first time?” 

I bit my lip and nodded lightly. 

“I’ve never kept anything from ya, Sats.”

She smiled. 

“And you’re sure you want… me?”

I snorted, and ducked my head into the curve of her hand. 

“Yeah.” 

Her smile was absolutely genuine. Nothing like the cruel, barely-there smirks of school, and not exactly the ones to humor me around the house. Her smile was full of… joy. 

And then she kissed me. Kissing Satsuki was so soft and warm, and I knew that this kiss was exactly how having sex with her would be. Slowly passionate and careful. But building up to something wild and electrifying. 

She rolled me on my back, and we continued to kiss easily. Her tongue and my tongue got lost in each other, and the rest of our clothes traveled the same path. 

“Jesus,” I whispered.

“What?” she smiled lightly, breathing elevated. I kissed her and stroked my hands over her curves. 

“Your tits are just as proportionate as your dick.” 

Satsuki laughed at me and toyed with my hair as she suckled on my chest, and I hiccupped a laugh. Our skin slid so smoothly together, and I started to ache, deep in my stomach. 

“Sats?” 

“Hm?” She answered, busy with nibbling my ear and throat. I skimmed her ass, and gripped her hips, getting her to focus. She did. 

“I’m ready,” I whispered. Her blue eyes flattened in lust, and she didn’t ask me if I was sure. She just stared at me. I nodded, and she rolled away, grabbing for the box of condoms on the nightstand. 

Satsuki quickly extracted one, and I felt my own dick throb with need. More persistent, was the pulsating of my vagina, and I briefly worried about Satsuki’s size. But I breathed, trusting my sister. 

Her perfect teeth ripped a condom open, and I smirked.

“That’s fucking hot,” I commented idly. 

She smiled as she carefully rolled the protection over her length, and it shone lightly with lube. Aw. How considerate of her. The constrictive rubber gripped my sister tightly, and I frowned in sympathy.

She mounted on top of me, and before I could get nervous, she kissed me deeply. I sighed into it and allowed myself to relax.   
I was ready for this.

If it was Satsuki, I was ready for this. 

Her cock bumped mine, and I knew I had to start right now, or I wasn’t going to make it. I kissed my sister with finality, and she took the hint. Satsuki lifted off of me and I spread my legs for her. I could feel the cool air hit my vagina, and I knew I had to be soaking wet. 

“Here,” she murmured, hands on my thighs, “Scoot up,” 

I shoved up the bed, my back resting on some pillows so I could see what was going on. Satsuki crawled to meet me, and she pushed my legs farther apart, sitting on her heels. 

“Ready?” she murmured, her eyes flat with lust and focus. I nodded, “Tell me right away to stop if I hurt you, Imouto, okay?” 

I shivered. 

“Okay,”

She positioned her dick at my vagina, and I held my smaller cock flat against my stomach. The head slipped through my folds the first and second push, but the third one found its way through. 

Losing my virginity was not as bad as some girls make it out to be. They’d had me convinced it was the equivalent of shoving a lit match up your hoo-ha. But honestly? It was a brief, sharp pain, and then it was over. 

I smiled as soon as it passed, but Satsuki’s face had drawn, and she bit her lip. 

“Ryuuko, there’s blood,” she said, worriedly.

I sort of smirked. It was an interesting turn of events, but Satsuki had always been a worrier. 

“Nee-san,” I quieted out, and I felt Satsuki’s dick throb, “Keep going.” 

Fuck, Satsuki was big. 

I whined and mewled like a kitten, but my sister pushed slowly and deliberately. Half-way through she stopped and panted heavily, and I knew my inner walls were spasming, trying to adjust. Eventually, I had all eight inches of Satsuki inside of me. 

It was fucking incredible. I was so… full. I’d never had something inside me, and the fact that it was my sister made my blood boil. I was panting, and my dick was straining. I grabbed Satsuki by the hair and kissed her as hard as I could. 

She felt perfect inside of me. My body was trying to adjust, but I honestly never wanted her to pull out. A thought dawned on me then, and I broke away from the kiss to rasp,

“Nee-san, take the condom off,” 

Satsuki looked at me colorfully, but she searched my face and kissed me again. So slowly I couldn’t tell what was happening at first, she pulled out of me slickly. 

When she was out, I knew I was right. I loved my sister inside of me, and I was going to get addicted to the feeling. Satsuki pulled the rubber off her impressive length, and it bounced free and hard as granite. The head of her penis shone, swollen and needy. Once again, she parted my folds and slid inside me. 

It was a lot easier the second time, but it was made absolutely perfect when Satsuki’s low gasp sounded in my ear. Her body shivered, and she whispered to me.

“Ryuuko, you’re so hot and wet. So warm,” Her voice was a desperate, wild rasp, and I felt my own precum slip over my dick.

I wrapped a fist in her long black locks. 

“You can’t knock me up, right?” 

She shook her head. 

“The chances are incredibly low,” 

I sighed, and shivered when the cock inside me throbbed. I gasped. 

“Are you alright?” she asked immediately.

“Nee-san,” I moaned. “Move,” 

Satsuki did. She started to gently roll her hips. Not even pulling out and back in, just a simple inch of leeway in and out, in a perfect circular motion. I loved every second of it. When I got used to the rhythm, she started to pull out a little bit more on every back thrust.

Soon, a soft slapping of skin on skin was heard, and I smiled. God, this was perfect. Satsuki apparently assumed that my body was ready enough, because she picked up the pace. I smiled. Not only did this feel amazing, but it was happening. I was having sex. With my sister.

She set a perfect, fluid rhythm. Two beats to pull out, one to slide back in. The draw was smoother than a bow, and the punctuation was the right amount of firm. And I felt everything. 

“Faster, Nee-san,” I begged, and Satsuki obliged, tightening her grip on the sheets on either side of me. A stead pounding started up, and I was bordering on understanding what girls meant when they said when they saw starts.

She straightened up, lifted my legs, and wrapped them around her waist, still moving in and out of me. Her hold was on my calves, and I was 30 seconds away from coming. Satsuki’s abs flexed every stroke, and her dick was just so perfectly big. 

Sats groaned deep in her chest.

“Ryuuko, your pussy-“ she huffed. “It feels so, so good.”

I wrapped my legs all the way around Satsuki’s waist, and sat up to hug her neck, and she leaned forward to rest her hands on the mattress again, picking up speed.

“I’m going to cum,” I rasped out. 

“Fuck,” Satsuki kept flaring her hips in perfect time. “I’m going to cum inside you, Ryuuko.”

“God, Sat- Satsuki.”

She panted in my ear. 

“Do that again,” she wined lowly. “Say my name, Imouto,”

I gasped.

“Satsuki,”

“No,” she grunted, sweat beading her forehead, “Tell me who you love, honey,”

Satsuki Kiryuuin was about to give me the best orgasm of my life and I was going to let her know who gave it to me.

“Nee- ah! – Nee-san!” I cried, panting and howling as her speed increased, pulling full out and slamming back in quickly. “Fuck, NeesanNeesanNeesan! Keepgoing, Onee! Please, more! Nee-SAMA!”

I felt a hot spurting inside of me, and Satsuki went rigid once, twice, three times, and I shivered, my climax absolutely rippling up and down my spine, my voice losing itself from my control. 

I honestly think I might have blacked out.

I came down slowly, and Satsuki had lain completely on top of me, holding me against her firmly. A final shiver from my sister, and I felt one last hot jet of cum paint the inside of me. 

“God, Ryuuko, you feel so good,” Satsuki moaned, and my internal muscles clenched to find she was still hard inside of me. She shivered from the roll of my flexing, and I put a hand through her hair, and one on her muscular back. 

I laid a kiss on the side of her head.

“Go again, Sats,” I breathed, and my older sister didn’t wait for me to tell her twice. Her long legs didn’t pull out as she rolled my hips up, her quads pressing into my hamstrings, feet on the bed. Her hands planted by my head and when she moved, her thrusts were almost animalistic. 

Inky black hair spilled down her front, and I reached up to gather the strands and held on for dear life. Her dick slammed into the tight channel of my body with all her weight behind it, and my breaths outward started to pitch upward as she hit a spot deep inside me. It felt like she was basically inside of my cervix, she was so deep. 

I was in heaven. 

Vaguely, between my breathy screams of pleasure, I noticed the bed squeaking like mad, Satsuki’s violent double-timed rhythm sending my bed springs into a cacophony. But in the moment, I was distracted. My ankles were locked high on Satsuki’s back, and she was absolutely going to town on me.

God, it felt so good. 

“Ryuuko,” she keened deeply, and we’d been having sex for all of 40 minutes, and I knew from her face that she was going to come soon. I dragged her head down to my mouth, and wondered vaguely if my sister shared my fetish for dirty talk. 

Either way, I’d better hurry, if she didn’t come soon, I was going to. 

“Nee-sama,” I begged her, my voice breaking in the rhythm she was fucking me in, “ah – Nee-sama, cum inside me,” Satsuki whimpered and started to thrust in a frenzy, her eight inches being swallowed inside me again and again. I was just saying whatever came to my mind now.

“Fill your little sister with cum,” it was all sorts of broken, but Satsuki got the message. She practically howled and bit down to kiss my shoulder. 

“Take my cum,” she grunted savagely, “Take it,” 

Satsuki’s low, animalistic voice combined with her perfect dick, hit just the right spot, and I came, ejaculating all over my stomach and chest. She came seconds later, my vagina already full of sperm, positively overflowing. The angle let me watch as cum leaked out, over even Satsuki’s penis. 

When she pulled out, it was with a satisfying squelch and a low, pulling sensation that left me feeling empty inside. I whimpered, and I felt the bed dip as my sister laid next to me, pulling me back into her arms. 

She cooed into my ear, and asked me over and over again if I was all right, kissing my shoulders and neck. I flipped and cuddled into her embrace, nodded tiredly. 

I just lost my virginity to my older sister. 

We laid together, cuddling and sated for long moments of drowsy contentment.

“Satsuki,” I rumbled lowly, and she hummed. “That was wrong, wasn’t it?” 

Her body stiffened, and I immediately backtracked. 

“I just mean it’s not ya know, something we should tell dad about, right?” 

She had opened her eyes and stared over my head, and I felt bad. Satsuki had been so sweet and patient, and I had gone and made her feel wrong. She had been so good, more than good; she had been fucking amazing. And now her warm arms had turned to frozen stone. 

“No, I suppose you’re right,” she said slowly, her voice taking on the professional tone of consideration I hated. “We should forget this happened. I’m sorry, Ryuuko.”

By the end of her speech, she had extracted herself from my limbs, and stood from the bed. I laid in shock as my sister collected her clothes and crossed to the door. 

“Wait, Satsuki! I didn’t mean-“

The door shut. 

Fuck.


	2. Chapter 2

**Summary for the Chapter:**

> Screw it, I'm just going to throw my whole story on here. You guys fucking rock.

I sat in one of the auxiliary student council rooms, and as head of the athletic committee, it was unspokenly my office. It was my safest space in school, away from adoring fans or otherwise. I had a corner that Ryuuko took as her own, and my desk drawer held teas, medicines, tissues, band aids, a spare uniform for both Ryuuko and I, lotions, and detention slips. 

I was currently breathing deeply and sipping a cup of tea, getting lost in my own head. I knew my Divas were concerned about me, but I didn’t want to explain myself. No amount of tea could fix this.

I had taken my little sister’s virginity. I had dreamed of it for a long time, had fantasized and visualized it until I was panting and desperate for any kind of release. But I never thought it would be so amazing. It was like I had had a vivid delusion. One where Ryuuko loved me like I loved her. One where she lusted after me in equal measure.

But no, she was right. It was wrong. I was wrong. And I was not one to admit when I was wrong. My musings were deep, and I realized that school had started a while ago. It was wrong of me to corrupt Ryuuko so, just because I wanted to. 

I was broken out of my trance by the jaunty tune of my cell phone, and I briefly recalled that Ryuuko had been the perpetrator of such an out of character ringtone. 

“Hello?” I answered mildly. What I called mild, many would most likely have called ‘darkly’. My sister’s panicked voice greeted me, and I instantly sat up in alarm.

“Satsuki?!”

“Ryuuko? What’s the matter? What’s happened?”

“Where are you?”

“My office. The right room of the student council area.”

“’kay.”

“Ryuuko, are you alright? Do you need me to send Ira?”

“No! Fuck, no. Don’t send anyone! Just stay there okay?” I pressed the phone to my ear and heard swearing and the rush of wind. “I need your help, just stay there.”

“Okay, Ryuuko. I’m here.” 

“’kay.”

And then the line clicked, and I sat back in my chair, thoughts whirling. I was sure Ryuuko was fine, but still, I was nervous for my troublesome sister. And for our upcoming interaction. I hadn’t allowed Ryuuko to open the topic of our afternoon together. It had only been two days, but Ryuuko hadn’t dropped the issue. She would pester me until I somehow changed the topic or left the room entirely. She was so obstinate. 

But I didn’t have the heart, or the courage, more likely, to tell my sister I lusted after her. I didn’t have the right. But she was so beautiful, and I had resisted so much. 

The door flew open and I tried not to startle. Ryuuko appeared, her hair as wild as always, and she shut and locked the door behind her. My concern lessened as my confusion rose. She seemed to be fine. A fever, maybe? Her face was bright red.

“I have a boner.” Her face was flaming, and her vocals ground out in mortification. I reeled back, letting my surprise show on my face. 

“I’m sorry to hear that.” I said eventually, letting my face relax. My eyes unconsciously lowered to where Ryuuko was clutching a notebook in front of her crotch. Ironically, I observed that one of her friends must have taken it at one point, as a crude sketch of a penis was on the cover. 

“Satsuki, I’ve had a hard on for two hours.” My sister whined, and I furrowed my eyebrows. “And I left my belt at home, so I can’t even tuck it up, and I have gym next period!”

Ryuuko was frantic, and my frown deepened. 

“Ryuuko, not having a belt is breaking the school dress code.”

“Satsuki!” She yelled. 

“I’m sure you’re embarrassed, Ryuuko, but I don’t know what you want me to do about it.” I replied, a low, hot feeling in my stomach telling me exactly what my sister wanted me to do about it. ‘Help her’ she had said on the phone. 

Ryuuko growled, running her free hand over her face. 

“I want you to get the fuck over whatever guilt trip you’re currently taking as a fucking vacation, and help. Me.”

“You want your sister to help you with the fact that you have a raging boner?” 

“It doesn’t matter that you’re my sister!”

I stood up abruptly, finding the end of my rope. “Of course it matters! You said it yourself – it’s wrong, Ryuuko! I refuse to be selfish enough to corrupt you!”

“Fuck you, Satsuki!” my sister roared at me, her fists clenched. “I’ve wanted you too, okay! It’s so goddamn egotistical of you to think you’re the one to blame, you know that?”

I listened, slightly stunned. 

“The goddamn fucking reason I can’t do it myself is because I only get off to thoughts of you! And so you’re going to fucking help me with this, because you’re my sister and I know you want me just as bad!”

I stared into Ryuuko’s raging, oceanic eyes. The same ones I had. My jaw worked, grinding my teeth, and I was so tired of fighting how badly I wanted to kiss her. Ryuuko was here, asking, and I felt my heart win as my will failed. 

I crossed to my glaring sister and practically snarled at her. I really didn’t enjoy losing, but I kissed her anyway. My sister was surprised and her entire body relaxed because of it. I lost my scowl and closed my eyes, pulling her into me. Ryuuko’s lips were softer than one would expect, and simply addictive. 

Eventually, I heard her drop her notebook and twine her fingers in my hair. I chuckled against her mouth as something hard poked me in the leg. Ryuuko released a strained huff and I leaned my forehead against hers. She opened her eyes to look at me vulnerably, and I couldn’t help but kiss her again. 

“Well talk about it more when we return home.” I told her seriously. “But for now, yes, I’ll help you.”

Ryuuko smiled brilliantly, relief spilling over her features, and I vaguely wondered if she had just come. I was certain she hadn’t, but I still watched her closely. 

“Did you just…”

“No!” 

I smirked. “Come on.” I lead her back to the chair I had been sitting at, and took my place back easily. I looked to her unsure face expectantly, and waved her over. “Sit facing me.” I instructed. I wanted to see my sister’s face as she came. It had been on my mind for two entire days.

Ryuuko shuffled strangely, then seemed to upset herself at her indecision. I smirked at her self-talk, and she straddled my legs comfortably, her hands resting on my shoulders. She grinned down at me, and leaned in for a kiss. 

I gave it without hesitation. Ryuuko was a surprisingly good kisser. While we busied ourselves with a play of dominance, I grasped her slim hips and played with the waist of her uniform pants, untucking her shirt gently. She shivered on top of me, and I smiled against her lips. 

“Ne, Satsuki.” she whined pitifully, bucking her hips lightly. “I’m already close, okay? Don’t tease.” 

I laughed, bringing her head down for another kiss just because she was adorable. 

“Okay, Imouto. I won’t tease.” She smiled against me and her lips wavered as I unbuttoned her pants and lowered her zipper. I glanced down to see her boxers tented and I smirked. 

“Ryuuko, shift a little.” I asked her, and she wiggled cooperatively enough for me to get her boxers and pants underneath her cute ass. I petted her hardness through her boxers, and she bit my lip in reproach. I pulled away from her and she set her head on mine. 

I kept pulling her boxer front down, and they finally slipped off her throbbing cock, her erection bouncing back up and twitching in time with the rush of her blood. I wrapped a hand around her 6 inches and gently pulled. Her dick was velvet soft, but still hard as wood, and I thumbed over the head of her spongy tissue. Ryuuko’s moaned growl pulled from her chest. 

I reached over and extracted the hand lotion I kept and released Ryuuko’s heavy dick to squirt some into my hand. I smoothed it over my sister’s throbbing cock and she moaned, a smile flickering over her face. Ryuuko had a very nice looking penis, especially erect. 

Now that I was able to study it without shame, I felt myself growing hard. It was perfectly straight, and not at all veiny. Though her size qualified on the higher end of average, my sister made up for it in her girth. Roughly, she was the circumference of a thinner bottle. The strangest urge came over me to kiss that lovely, circumcised head, but it really wasn’t the time. 

“Nee-san,” Ryuuko said, grinning as I worked over her dick with skill, “Are you hard?” 

“It’s possible.” I reply shortly. I don’t like to do things by half, and I was focused. 

“It’s poking me in the ass, Sats.”

I hummed and smirked at her wickedly, “That’s not a bad idea, Imouto.” The smile slid off her face and I chuckled wonderfully. Ryuuko was just so cute. The blush on her cheeks proved it. But that also could have been because her sister was currently giving her a handjob. 

I refocused on her, and tested what she liked. Base to tip, I stroked and changed pressure, twisting my wrist and sometimes keeping it locked. Her penis was jumping in my hand, and her thighs flexed over me as she squirmed in luxury. 

Observing enough, I decided she was ready to cum from the way she was biting her lip. With my clean hand, I quickly snatched a tissue from the box on my desk, and prepared myself to catch Ryuuko’s semen. 

I sped up slightly, and admired how her testicles were small and perfectly symmetrical. Ryuuko gave a whine and grit her teeth, arching into my hand. Thankfully, I was ready with the Kleenex, or I would have needed to clean much more than just her dick. 

“Ohhh,” Ryuuko moaned from where she had slumped against me, “Oh, God, thank you so much. That feels so much better, Nee-san.” I felt her kiss under my ear and I squirmed lightly. It was a ticklish spot. 

Wrong reaction. My sister laughed and nuzzled the spot with her lips and tongue, and the pressure in my pants increased. Feeling the strain, Ryuuko leaned back and grinned. I rolled my eyes at her, raising an eyebrow. 

“Well?” I demanded. Ryuuko cocked her head, and I smirked. “You owe your big sister now, don’t you?”

Her eyes widened and glanced down, licking her lips nervously. “Satsuki, are you serious?” 

I nodded, leaning back in the chair and peering at her. “I haven’t come in almost three days, and you have a responsibility to finish what you started, Ryuuko.”

She bit her lips, this time in nervousness, and I took her hand, kissing it gently. Her eyes looked at mine, searching. I flicked a suggestive glance at my crotch, and she snorted, climbing off of my lap. She rearranged her now-soft dick back in her pants and tucked her shirt in. 

I opened my legs wider, and she blew air through her nose, narrowing her eyes at my hidden erection like it had personally offended her. I leaned a few fingers on my temple, waiting. 

In one heavy motion, Ryuuko crouched on her knees, and the vision put even more pressure in my penis. My little sister was on her knees, her fingers working at my belt buckle, a fiery kind of determination behind her eyes. Every fiber in my body immediately went on high alert. 

Ryuuko peeled my pants away, and I was bulged against my underwear. She gave a sort of smirk at the clear outline of my penis, and I tightened my jaw as she extended a hand to stroke my length through the fabric. 

I suppressed a sigh as her fingers grew bolder, my dick hardening with each pass of her hand. I was frowning in controlled concentration, and I grit out in warning, “Ryuuko.” 

“Yeah, yeah,” she pandered, finally reaching to my hips, “Up,” she commanded, and I didn’t move. She glanced at my face, and I raised an eyebrow before she rolled her eyes, “Please?” she tossed out. 

I nodded and raised my hips, letting her tug my pants and underwear down, and I quickly caught my erection before it slapped against my uniform jacket and spotted the pristine black with precum. 

“Please be careful,” I murmured, and Ryuuko’s face flamed as she leaned toward my length, her courage fading. She nodded and replaced her smaller hand with mine, pumping my shaft softly. Ryuuko leaned forward and hesitated slightly. I could feel her shallow breath on my sensitive head, and my erection strained in her hand. My heart softened. 

“Imouto, it’s alright.” I said quietly in the stillness, carding a hand through her wild and soft hair, “Just relax. Watch your teeth and breathe through your nose.”

My sister’s hesitant look cleared and she nodded, leaning all the way over, opening her mouth and taking a tentative lap at my hot, trickling head. I felt it like an electric shock, vibrating down the length of my dick, to the base of my spine. She repeated the lick, and seemed to gain confidence and speed, her tongue flattening and twisting around the sensitive head. 

I kept a hand in her hair, but didn’t push. The extended feeling of her head moving over my dick was exhilarating. Suddenly, she shifted, and the head of my cock was covered in a warm, wet sensation as she took me in her mouth, Ryuuko’s tongue still swiping the sensitive underside. 

A moan accidentally slipped out from between my teeth, and Ryuuko hummed. The vibration curled my stomach and shivered up my spine. My sister pulled off my dick, and looked up at me while she pumped, a smile curling her mouth. 

She looked genuinely happy, and I felt my eyes crinkle in amusement and affection. 

“Nee-san,” she managed, an accomplished gleam in her eyes, “You taste fucking great.”

My dick throbbed, and my hand twitched in her hair, those feather-soft locks slipping through my fingers. That was the exact last thing I had expected her to say. But shame on me for underestimating my little sister. I smiled, reaching my other hand to stroke her cheekbone fondly. 

“I’m glad you’ve found a new hobby.” I smirked, “Keep going, and you’ll taste something else.”

Ryuuko’s eyes sort of widened, like she had forgotten about my orgasm, but they then darkened, and she placed a hand on my thigh. Her lips parted, and she leaned to envelope my cock once more. 

I struggled not to push her head down my length impatiently, but I loved my sister much too much to hurt her. There was something wonderful about the slow, learning pace Ryuuko set that was incredibly sweet. A prideful part of my heart swelled, knowing that I was my sister’s first everything. 

She carefully bobbed a bit lower, taking more of me into her wet mouth, her saliva dripping down my cock, and she pulled off every now and again to lick my underside. She went so far as to keep jerking my dick and suck one of my testicles into her mouth, kissing and licking the base. 

A low humming had started in my chest, and my eyes were locked on Ryuuko’s methodical work. Every now and again, her eyes would flicker up to meet mine, a dark look that peered through the fringe of her bangs, and it sent my dick throbbing even more so. 

I bit my lip, and Ryuuko’s eyes lit. 

“Imouto,” I groaned lightly, the pressure in my penis building hotly. She opened her jaw widely and took as much length as possible into the warm recesses of her mouth and started to bob gently. 

I gave a strained huff of air, shivering. The spongy tissue at the head of my penis hit the back of my sister’s throat and the lights in the room sharpened in front of my eyes as she gagged, her throat constricting around my dick. I fisted her hair and my thighs flexed, the feeling tight and blissful. 

“Imouto.” I growled deeply, and her blue eyes flickered to me, my cock still in her mouth, “I’m going to come.”

Ryuuko pulled to the top of my penis, only the head in her mouth, and my hands locked in her hair. She cradled my balls gently in one hand and pumped my lengthly shaft with the other with careful rhythm. 

“Oh.” I groaned, “Ryuuko.” I was close, so close. This was it. I bit my lip.

My sister kept her eyes on me, and suckled softly on the head. The increase in pressure created a vacuum, and it was everything my body needed. I tried to keep control of myself and not rip her hair out, but my arms flexed, and my shoulders arched back into my seat, my whole body tensing. 

My abs tightened uncontrollably, and the arch rolled through my body until it released itself through my erection, cum jetting out and into my sister’s hot mouth. I shivered and tensed as I spurted in searing streams, watching as Ryuuko’s eyes widened in shock and alarm. 

I finished in a few drawn-out moments, and she leaned away from my dick, a strain of cum leaving a trail from the tip of my cock to her lips. Her tongue darted out to clear it, and I saw the shining whiteness of creamy cum in her mouth. 

Instantly, I was leaning forward, shifting my hands to hold my sister’s jaw, feeling her musculature. My eyes narrowed slightly and her gaze was locked on me. 

“Swallow it.” I demanded softly, “Come on, Imouto. Swallow.”

Ryuuko’s throat flexed under my hands as she drank, and I watched closely as her facial features twisted in surprise. I felt her swallow against my hands once more as she worked to clear my semen from her tongue. Her deep-sea eyes were slightly vulnerable, and I knew this was a role-defining moment for us. 

I leaned even further forward, shifting my weight in the chair, and kissed my sister deeply. She hesitated for a split second before kissing me back, and I didn’t wince as my own taste presented itself on her tongue. I languidly kissed her into relaxation, and she eventually sat on her heels, letting me comb my fingers through her hair. 

Trying my best, I told her everything was fine in the passes of my tongue over hers. In soft sucks on her bottom lip, that she was wonderful. I felt her hand lightly stroke my thigh, and I gave another pleasant kiss before letting her go. 

She stood and I re-arranged myself to be presentable as her familiar iron backbone regrew in her posture. A tentatively arrogant look entered her eye, and I sent her a look. 

“Come on, Ryuuko.” I walked to the door and she followed wordlessly. “Get to class. When we get home, you’re going to explain to me exactly how and why you’re so good at that.” My tone was stern, but Ryuuko blushed and smiled rakishly. 

She suddenly turned her gaze to the side, her expression pained, and I raised an eyebrow. 

“Nee-san.” She edged out, suddenly diffident.

Her face turned back to me, rocked slightly on her toes, and I understood, entertained. Removing my hand from the door’s lock, I wrapped an arm around her waist and pulled her body flush with mine. I declined my head and my sister leaned up, bringing our lips together in a gentle, caring kiss. 

I let her satisfy whatever emotion was currently occupying her mind with my lips. I had a sneaking suspicion she was trying to regain some semblance of dominance, and I didn’t try to correct her.

A chime sounded over our heads, and I shooed her to class with the authority that I was aware she hated. She went with a fantastic eye roll, and I re-shut my door. My first two periods had been free, but now I, myself, had class. I gathered my things and headed to my advanced placement English lecture. 

Three of my four best friends shared the class with me, and they each sent me variations of concerned looks. I simply nodded to placate them, and sat fluidly, waiting for my lecture to begin. Already having accomplished the homework for the following lesson, I allowed my mind to run its own monologue, something I rarely indulged in. 

Ryuuko had performed oral sex for me. My little sister, down on her knees, her head bobbing in my lap, gagging on my erect penis- 

I shut my eyes and blinked back open. That was an entirely too inappropriate picture to have in class. Somehow, it felt wrong to even think of it in a public sphere. The image was private, as are the preceding and following scenes. 

The following scene of Ryuuko’s startled expression, and my subsequent soothing to her. At the time, it had been instinctual. Given time to mull it over, I knew why my sister had needed the reassurance. Ryuuko was nothing but proud, something she and I share. She kept her head held high, and apologized to no one for it. No one except perhaps me. 

So when she gave up that pride, and quite literally lowered her head to please me, I hadn’t wanted for a moment for her to think the act made her subservient to me. In all reality, it was true to a degree, but not to the extent any crack of insecurity might lead her to believe. 

Afterward, my arrogantly self-sufficient little sister had been almost… docile. Subdued, in a way. I supposed a stomach full of semen would do that. It had been her first time being so intimate, and I felt my thoracic cavity heat as I wondered if I did right by Ryuuko. She trusted me, and I would die before I betrayed my little sister’s trust. 

Though she hasn’t been little for a very long time. 

I roused my conscious and focused on the lesson. These musings would have to wait for after school, when it was only Ryuuko and I. Then, I would ensure everything was in its rightful place. 

Assuring what the school had started to call my ‘Devas’, I placated my friends. They had merely worried about my quiet for the past two days, but Ryuuko had come to me, and my conscious was clean once more. Eventually, they settled, Nonon being the last. 

I attended a student council meeting after school, and reported on any updates I took responsibility for. An hour of deliberation passed, and I paid the utmost attention before the meeting was adjourned. 

The vice president stopped me from leaving to once again try to discuss something asinine with me, a cover for his real motive of trying to ask me out, and a well placed growl from my friends Ira and Uzu sent him on his way. I had no patience for fools like he. It was a disgusting display of leadership, and I noted not for the first time that my office will never display such clumsy authority. 

Stopping by my office with my friends in tow, Ryuuko quickly looked up from her books and packed her things. My eyes tracked her movements while Uzu and Hoka argued behind me. My fingers twitched as she drew near us.

For an inexplicable reason, I craved badly to touch my sister in some tangible form of greeting. Ryuuko’s eyes swept over mine, and I wanted to reach out and bring her into a kiss, physically manifesting my adoration for the way she grinned at me. She took her place behind my friends and switched to glaring at Nonon, who stared defiantly back. 

“Kiryuuin.” Nonon noted.

“Jakuzure.” Ryuuko replied in distain. 

“Delinquent.”

“Troll doll.”

“Thief.”

“Kiss ass.”

“Pissant.”

“Enough.” I cut, and all of my Devas quieted, “We are still on school grounds, Nonon. You are better, and held to a higher standard than the average student. You disappoint what we represent when you are seen having childish squabbles in the hallways like some common teenager. That goes for all of us.”

“I’m sorry, Satsuki-sama.”

“I apologize as well, Lady Satsuki.” Ira intoned, “I should have stopped them.”

I waved a hand, “It is forgiven. We are all responsible for the collective’s image.”

We continued walking, a subdued conversation bouncing between my friends when I reached my car, and my Devas told me goodbye. Uzu was the only one to tell Ryuuko the same, and my eyes caught his too-friendly smile. I would deal with that later. 

I got behind the wheel and started the Audi TTS, the wonderful purr warming my heart. Ryuuko ducked in and buckled her seatbelt, looking out the window quietly. I peered at her quizzically, but didn’t push. 

With the silence to inadequately distract my mind, my thumb tapped the shifter in a mindless staccato. I noticed movement to my right and Ryuuko suddenly moved to cover my hand with hers, stifling the sound. I shot her a look, and noticed her ears were slightly red. 

The why came a moment later, when her fingers found the spaces between mine. The sound of the car’s 292 horsepower engine was nothing compared to the hot fluttering that entered my chest. Without a word, I removed my hand from the stick and quickly re-captured Ryuuko’s smaller, slightly rougher, hand in an alternate grip. My eyes didn’t stray from the road as I laced our fingers together, extending my arm just the slightest bit to rest our joined hands on my sister’s lap. The cab was incredibly compact, and it wasn’t a stretch at all. 

Pulling to a stop light, I glanced at Ryuuko, who returned my look with her comfortable smirking expression. I allowed a fraction of a smile. 

“How was gym?” I teased, my voice softer than anyone at school had ever heard, Nonon included. 

Ryuuko snorted. “Thankfully, a lot less hard than I thought it was going to be.”

I laughed shortly, and the light turned green. My sister stroked the back of my hand with her thumb and started to explain the apparently moronic gym partner she had the misfortune of being paired with. 

We turned into our house’s driveway, and I was frowning. 

“What did you say his name was?”

“Tate Yuuichi.” She responded, letting my hand go and exiting the vehicle when the garage had successfully shut. “Which really sucks because I’m pretty sure he has a girlfriend. Or maybe they’re just talking.” 

“I’ve heard of him.” You comment, following her into the house, “I believe he’s on the kendo club.”

Ryuuko sent me a playful, challenging look. “You’re not gonna have him taken out or something?”

I lifted an eyebrow, “He molested my little sister. I’m going to have him murdered.”

She shrugged, tossing her school bag on the kitchen counter and folding her hands behind her head as she walked to the fridge, “I think ‘molested’ is a strong word, Sats. He just tried to accidentally kiss me or some shit. Tch. Idiot. Like it was some shoujo anime.”

I frowned, crossing to where she stood, and shut the fridge door forcefully. She spun, and found herself face to face with me, looking up into my eyes. My hand was still on the door, and I brought my other one up to her face, brushing my thumb over her lips. 

“Today,” I whispered, gently parting her delicate lips, “You kissed me and swallowed my cum. Tate Yuuichi gets no part of that.”

Ryuuko’s eyes went cloudy, and the next thing I knew, her tongue was in my mouth, and she had jumped, my arms instinctively catching her. We kissed heatedly, passionately, and she tore away from me to breathe. 

Her forehead set on mine and we reentered the kiss, slower than before. Languidly. Her legs were wrapped around me, and I walked with slow steps to the living room, pushing her back through the swinging door. 

“Ryuuko.” I murmured between kisses. She unlocked her legs from around me and slid down my front to her feet. “Imouto, we should talk.”

“Yeah.” She agreed, nodding. She broke away from me and sat on the couch, taking her blue uniform jacket off and throwing it over the back. I sat a polite distance away, and undid the top button of mine. 

My sister sat, and her thoughts were practically visible, they were flying so quickly. I pursed my lips. There was a high probability this conversation would be uncomfortable, but I had learned to stop underestimating Ryuuko. My sister had a recurring habit of – 

“I want you to use a condom!” She blurted out, sitting on her hands. 

\- Surprising me. 

“Pardon?” I asked, eyeing her flushed, angry face. 

“When we fuck,” my sister elaborated in short bursts. “I want you to wear a condom. I know it sucks. But even, ya know. A low chance. Is too much. I just don’t wanna get pregnant, okay?”

I paused, processing. “So you want to continue this?”

“Of course.” Ryuuko said, like I was some kind of dimwit. 

“Okay.” I responded, then thought of her words. I pictured it, and frowned. But nodded. “A condom is probably for the best.” 

I tried not to pout in front of Ryuuko. The first time I had entered her had been with a condom, but I had taken it off almost immediately. The difference in feeling was staggering. It was the disparity between performing brain surgery with latex gloves, as opposed to oven mitts. 

My sister laughed at me openly, and I looked away. Her eyes had softened in what clearly told me she thought my grimace was cute. She scooted across the couch, extending her legs over my lap, and laid a small kiss on my turned cheek. 

I felt another bloom of heat across my nose and swiveled my head forward so she could access my lips. My eyes slid shut, and she smiled against my mouth. I leaned away and sighed. 

“Yes, a condom.” I agreed, and decided to let my nose wrinkle, “But I don’t have to like it.” 

Ryuuko laughed, and I smiled at her. She gently head butted my shoulder, bringing her arms up to wrap around me. I cleared my throat, bringing a hand up to count off, while I supported her back with my other. 

“So.” I began calmly, “Masturbation, mutual masturbation, vaginal sex, oral sex.” I lifted an eyebrow, “How do you feel about anal sex, Imouto?” 

Ryuuko shifted in my arms, and she tilted her head, “I- I mean, I’ve never really thought of it. I mean, there’s that whole prostate thing, which I guess would feel good. I dunno.” She sounded genuinely confused, and I was relieved not to find any fear behind the words. 

I laid a kiss to her forehead and delighted in my ability to do so. “Well, think about it?” 

My sister nodded, considering. To be truthful, I was curious about the sensation, but the logistics didn’t excite me. It didn’t seem incredibly sanitary, and I wasn’t eager to hurt Ryuuko to satisfy a wondering whim. 

“Ne, Satsuki.” my sister called my attention and I granted it, focusing on her curious face, “Can we do what we did today? But like, a lot?”

“You want to go down on me a lot?”

Ryuuko barked a laugh, and I grinned. 

“Well, I mean, kinda?” She struggled for words and hid her face in my shoulder disguised as another head butt. She emerged and glared at me lightly, “I mean, when one of us gets a hard on in school. Can we, ya know, help each other out?”

I tipped my head and frowned, “Ryuuko, having sex on school grounds –“

“We already did it!” My sister complained, scowling. 

“It was an emergency.” I brooked, sending her a significant look, and she stared back challengingly. 

“That’s exactly what I’m talking about!”

I clenched my jaw and breathed deeply, “I… I suppose, Ryuuko. But only if it is an emergency. If you’re just horny, keep it in your pants until we get home.”

“Whoo hoo!” Ryuuko cheered, fist raised. I rolled my eyes. Mentally, I was calculating all the safe areas to ravage my little sister in during school hours when she undoubtedly abused my good grace. 

“Sats, what about Dad?” 

I raised an eyebrow, “I don’t think so, Ryuuko.” I said softly, looking away from her frowning face, “I don’t want him to think he tried his best and I turned out like her anyway.”

Ryuuko had gripped my chin in her fingers and turned my face back to hers in an instant, her eyes burning. 

“No.” She thundered, as serious as I’d ever seen her. “Satsuki, don’t even go there. You know there’s no comparison. Tell me you know that.”

I nodded evenly, my mind resting, “I do. But it was a thought I had.”

My sister glared at me carefully, then nodded, dismissive, “Well… Good.” She shifted her weight and yanked on my shoulders until I followed her into lying on the couch. She spooned against me and I kissed the crown of her hair. 

“I’m glad you’re not freaking out anymore.” She muttered after a moment, and I smiled lightly. 

“Me too.” 

She tossed restlessly and turned to face me, a hard glint in her eye. I brushed the bangs out her face and asked her what she was thinking. 

“What time did I blow you?” she asked, and I considered. 

“9 or 10.”

“And what time is dinner?” 

“Whenever I see fit to make it.”

“…right. So. Maybe we could fuck before?”

My penis found that question very interesting, and I let it show in the excited gleam in my eyes. Ryuuko smiled, wiggling forward to eskimo kiss my nose adorably. She reached down and started rubbing me through my pants. 

“Ryuuko, if you do that, I’m going to get hard.” I cautioned, and my sister laughed wickedly. 

“That’s the idea.” She taunted. I smiled, accepting her challenge. Then, a thought occurred to me and I gripped her moving wrist, stopping the erotic motion. Irritated, I pushed off of my sister and slid to my feet, stalking away from Ryuuko. 

“Hey!” She shouted after me, “Where are you going?” 

I stopped my retreat and whirled back around to glare darkly at my younger sister. Gathering all of my dignity and mixing it in a vast ocean of disgust, I growled out, 

“To get a condom.”

Ryuuko laughed and laughed and laughed.


	3. Chapter 3

“Why did she get the window seat?” I whisper into the thick black of Satsuki’s hair petulantly. My sister sends me a stressed look of warning and I huff, looking back across the aisle. Gamagori, Hokka, and Uzu were seated across from us, and I grinned at the irritated look Uzu was giving Hokka for crowding his space. Something he couldn’t help from the sheer size of Gamagori. 

I suddenly feel the heat of my sister’s lips near my cheek and her cool breath ironically warms my ear as she speaks above the whine of the plane, but below the quiet cabin. 

“Nonon gets airsick, Imouto,” she explained gently, trying to reason with me, and I scowled. 

“I told you weeks ago that I wanted to see us fly over it,” I complained, and Satsuki pursed her lips, frowning. She opened her mouth to respond, but turned her attention to her other side, and I heard Nonon’s annoying vocals. 

I scowled to see the twerp had put her hand on Satsuki’s blanket-covered thigh as her means of gaining my sister’s attention. I really don’t like sharing Satsuki. Especially with Nonon. But Satsuki had promised she’d spend time with me this summer, and an unplanned college visit had interrupted that time. 

So I joined it. Never too early to start looking at higher education, right? At least, that’s what I told Dad. Which was fine, but a total lie. I could give a shit about this. I just didn’t want Nonon and Satsuki in a hotel room together. 

All sorts of shitty rom-com plots started that exact way, and I’d rather have a full-length conversation with the pink-haired cunt rocket than let that happen. Which says something about how much I hate talking to the bitch. 

So I frowned, and then grinned wickedly. I know something Satsuki might find interesting. I glanced around me and smiled even more deeply. I felt like a goddamn villain, but what did I care?

Slowly, I elbowed the armrest between my sister and I out of the way, and then placed my hands under my own blanket. Carefully, I slid my closest hand into the space between us, and my fingers curled up and around the muscle of her thigh, incredibly high on her quad. 

Instantly, Satsuki froze, and she made a controlled reach under the seat in front of her to retrieve a book she was reading. She turned her sharp eyes to me and snapped as she readjusted her blanket, opening the book in her lap. 

“Ryuuko, what do you think you’re doing?”

I could only smirk at her and whisper, “Getting you hard so we can fuck in the bathroom,” I grinned, “Duh,” 

My sister seemed to have no idea what to say to that, as she blinked slowly and let her eyes wander over the passengers of the plane before re-settling on me. 

“Please tell me you’re joking, Ryuuko,” she panned dryly, and I fixed her with a challenging look, one that I knew she was well acquainted with. She frowned heavily, and I crept my hand even further to slide inside her thighs, cupping her crotch. 

I sent her a raised eyebrow and my sister averted her eyes, muttering something about ‘air pressure’. I only bit my lip, checking to see if any of her Devas or a flight attendant was paying attention. Feeling no heat of a gaze, I experimentally squeezed Satsuki’s already-hard member tucked down the leg of her pants. My sister twitched. 

Satsuki didn’t take much to come. But my sister had a will of absolute iron, and usually elected to hold out for as long as it took to please me. Still, she was sensitive as fuck. I grinned, sensing victory at hand. 

I glanced away from Satsuki and tried to look bored as I circled the head of her penis with my thumb. Slowly, gently, I caressed Satsuki’s length into marble hardness, and I knew she was about to lose her mind. 

Finally, I felt a pressure on my wrist and looked at my sister. Her cheeks were flushed, and she looked as if it were taking a monumental effort to keep her facial expression from twitching. 

“Ryuuko,” she said lowly, her slim fingers wrapping around my wrist completely. I felt my breath catch and my heart speed as her beautiful face descended to speak to me privately.

“Listen to me very carefully,” Satsuki smoothed out deeply, her eyes focused, “You are going to hurry to the bathroom in the back of the plane and look like you’re going to be ill. I will quickly inform an attendant that you’re going to be sick, and I’ll assist you. Understand?”

I tried to stop the slow smile that spread across my face. Satsuki wanted to get it on. I couldn’t believe it. My sister rolled her eyes briefly at my look of fleeting glee before she fixed a more focused look of warning at me. I bit my lip and nodded. 

Jesus, I was already hard. 

I extracted my hand from Satsuki’s blanket and cleared my throat, focusing. How to look sick. Look sick. I took some deep breaths to flush my face and screwed my expression up in nausea. 

I glanced at my sister as if I were worried, and Satsuki’s eyes glinted in affection before clearing and nodding her approval of the face. 

I wanted to kiss her so bad. 

Instead, I unbuckled my seatbelt and lurched to my feet, swaying slightly. I felt eyes on me as I quick walked to the back of the plane, one hand on my stomach, the other fist on my mouth. I heard Satsuki’s smooth strides fall behind me. 

I practically kicked open the thankfully empty bathroom and shut the door behind me, not locking it. Shit, the room was tiny. We’d really need to maneuver in here. 

Still, though, I felt myself smile hugely. We’re in. I could already feel blood rushing to my dick, and I didn’t resist the urge to unbuckle my pants and start stroking my cock. Oh God, it felt nice. I set a hand against the counter sink and let my head hang as tension flew out of my body. 

The door opened, and Satsuki’s tall frame slipped through, shutting and locking the door behind her. I cupped my crotch and sent her a hungry look. Her oceanic eyes, so like my own, flattened in a millisecond to the lust-filled cockiness that was mine and mine alone. 

She was practically already pressed up against me in the confined space, so she only had to lead down to press a kiss to my waiting lips. I hummed into her warm mouth and parted my lips when her tongue brushed them. 

We kissed deeply before she broke it. There was only one sound that emitted from my sister, and it came husky and from deep in her chest.

“Hurry,”

I immediately stripped my jeans and underwear to my ankles. Goddamn, I was horny. I didn’t realize how badly I wanted Satsuki until we had been confined together without being able to touch or kiss, and I was just enough of a selfish little shit to want her always. 

Honestly, I just wanted to come. And I couldn’t do it without my sister inside me. 

Satsuki had taken her pants to her knees and sat on the closed lid of the built-in toilet. It was more of a shelf than anything, with side rails and walls. I smiled as she grinned and twirled a finger to tell me to turn around. 

Satsuki’s dick stood tall and twitching and I swallowed, turning my back on it. I reached to grip one railing on the wall and placed another hand on Satsuki’s thigh as I guided myself to straddle her legs backwards. She wrapped her hands around my hips and helped place me until I felt the hot prod of her erection against my ass. I bit my lip, focusing. Had to be quick. 

I was absolutely soaked, and I reached under me to place her tip to my entrance and quickly sank so my sister was plunged deeply inside of me. I moaned, and Satsuki’s grip on my hips tightened. 

The cabin was so small I could place my hands on the door, bracing myself. So I started to bounce, my feet planted, and Satsuki’s dick fitting so snugly inside my womanhood. She slid in and out of me, and I felt the friction of her with every measured rise and fall of my hips. 

Over and over, I pulled up and down on her lap none too gently. She felt so good, and I was practically whining from her length inside me. 

“God, you’re so big,” I keened, and Satsuki gave a satisfied rumble. Her hands moved, one pushing my back forward so I truly braced my weight against the door, the other placed under my ass to hold me slightly in the air. I felt her shift under me, her hands leaving my body. I almost cried out when Satsuki started to jackhammer into me, her speed absolutely mind blowing. She had put her hands on the toilet lid to leverage herself in the air to have a pushing off point to pound into me, and God, was it bliss. 

“Nee-sama,” I whimpered, biting my lip. Satsuki felt so good inside of me, stirring me so deeply. The wet slap of my juices against her flexing thighs, the heavy pants of my own breath being driven out, and the pleased groaning of Satsuki drove me insane. 

But Satsuki was fucking me so rawly, I eventually started to blank out. My gut was pulling low and my vagina was full and in use, putting pressure almost directly behind my dick. I felt my legs starting to shake, and I knew my insides would be tightening and roiling. Because Satsuki had found that ridge inside of me, where the perfection of her cockhead continuously caught, and my insides were so tight, I felt it dramatically. 

“Ryuuko,” Satsuki throated out in caution, and I nodded my head quickly, feeling myself build and build and build. She shifted quickly to place one hand squarely behind her, and another pulled me down by the shoulder to land in her lap on each stroke upward, improving her already direct aim.

I shoved my first knuckle into my mouth to bite down the scream I almost let slip. My orgasm was almost here and I kept bracing against the door, taking Satsuki’s pounding. 

“Imouto,” Satsuki growled in her chest, her breath contorting the sound to make it a huffed strain. My insides flexed and I was so, so, so close. 

“Hold on, hold on, hold on,” I chanted, feeling my orgasm start to descend down my spine. 

“Ryuuko, I want to come inside,” she grunted, and I bit my lip, the lights dancing in front of my eyes. 

“No!” I whined, “Pull out,” 

As soon as I felt Satsuki shift to slide out of my aching depths, I slammed my hips backwards with a clench of teeth, “Don’t you dare pull out,” 

Satsuki growled and re-started her fucking, her movements borderline vicious, and getting wilder by the second. I don’t know what was going through my sister’s head, but it felt a lot like her other head was going through my cervix. I bit back another howl and my pussy clenched even harder. 

“Ryuuko, relax honey, you’ll break me,” Satsuki rusked, and I followed her advice. As soon as I had forced my insides to uncurl, the glans of my sister’s dick pulled backwards over the ridge inside me once, twice, and I arched up and backwards, shoving two of my knuckles into my mouth. 

My sister sat instantly, grabbing a hold of my dick’s head with one hand. I came all over her quick digits without thinking, and I felt her exhale and shudder with a whimper, my insides growing hot. 

I had a glorious amount of hang time, my shivers wracking my body and clenching and unclenching around Satsuki’s dick. My sister only stroked my cock slowly with her clean hand, milking me for cum sensually. When I finally came down to Earth, I was grinning and slumped backwards on Satsuki. She craned her neck to kiss my cheek, and I turned my head to brush my lips against hers. 

“I love you, Ryuuko,” she hummed, her eyes oceans of truth. 

I smiled, my heart softening, “I love ya too, babe,” I shifted my eyes from her and raised a brow, “How long has it been?” 

My sister checked her feminine watch, “Seven minutes,” 

I grinned wickedly, still seated on my sister’s softening penis, “So you’re telling me that I just raw rode my way, reverse cowgirl, into the Mile High Club, while going the distance in Seven Minutes in Heaven?” 

Satsuki hummed, scratching at my back lightly, “I suppose we may have set a new record for ourselves, my love,” 

I smiled not only at her address of me, but at the fantastic sex we had just had. I sighed, “That was amazing,” Satsuki smiled and kissed my clothed shoulder. My sister was never one for speaking after sex. She was more of a ‘bask-in-the-afterglow’ type girl. Still, I had a point to make, “Can we not ruin it because Nonon’s a jealous cow?” 

My sister laughed, “And what do you think will prevent that?”

I huffed and made to stand in the tiny space. I managed it, and Satsuki’s dick fell out of me, making me shiver and give a hitching exhale. 

“How about every time she speaks over me, you remember that I’m sitting two inches away, and full of your cum? 

Satsuki’s eyes glinted, her ego nearly the size of her dick, a possessive, proud tint to her smug smile. I grinned. My sister loved coming inside of me. I didn’t know why, but it made her so happy. Probably some kind of dominant ownership type weirdness. But when Satsuki was happy, I was happy, so I let her glow in her accomplishment. 

And truth be told, I liked it when she came inside me. I know that’s fucked up, but Satsuki’s hot cum painting my insides was fucking addicting. And knowing that that seed of her desire was still in my most secret and coveted place, it felt like I had some proof of her love. 

It’s fucked and I know it, but I can’t help it. We could never have a kid. The genetics are too dangerous. So it was either birth control or condoms for us. And seeing as all the extra estrogen from birth control would fuck with my already precarious hormonal balance… condoms it is. Which my sister was anything but happy about. 

What else was there? 

By the time I was done pondering, Satsuki had stood and fixed both of our pants back together, and was drying her hands on a paper towel, her chest to my chest, the cabin was so tight. I threaded my hands through her hair and laid a loving kiss to her lips. She hummed contentedly, pulling my hips to hers. The plane below us rocked and roiled. 

“You’ll need to look as if you’ve been vomiting,” my sister placed my hair behind my ears, something she was fond of doing. She said it made my face more visible, “Just go back to our seats and let me handle the rest,”

I nodded, turning to the door. I unlocked it and held a hand over my mouth, pinching my eyebrows together fauxly. I saw a worried-looking flight attendant glance me over, and I hopefully was flushed and slightly sweating enough to make it look like I hadn’t just taken it from behind. I continued walking and heard Satsuki’s dulcet tones address the stewardess. 

I distinctly heard the words ‘my sister’, and I resisted indulging a smile to find that our perversion was also our savior. I slid into the aisle seat once more, and closed my eyes. Best. Flight. Ever. 

“Christ, Pukes, and I thought I was bad,” Nonon snickers. 

Nevermind. 

I turned to glare at the girl, seated snug and smug against the window. I pulled my lips into a snarl. Quietly, I bit, “At least I don’t look like I should be in a Happy Meal,” 

“Fitting, how without Satsuki-sama, that’s all you could afford!” she hissed, and I bit back my acidic reply when my sister virtually climbed over me to seat herself between us fluidly. 

She turned hard ocean eyes to Nonon and said something I couldn’t hear that made the girl look slightly ashamed and turn to the window. My sister focused her attention back on me and I tried not to look guilty, still pissed that someone so small could be such a bitch. 

“What?” I complained defensively. Satsuki glanced across the aisle and leaned down toward me minutely. I turned my head to allow her access to my ear, and she spoke huskily into it. 

“Imouto, I know you’re not happy that they are here, and I’m sorry for that. But I promise I’ll take you somewhere else another trip, just the two of us. I love you very much, and I want to give you that, honey, I do,” she let her lips brush the outer shell of my ear and I bit my lip, “But this time is for business, baby. Please don’t make it personal?”

I was being childish, wanting my older sister all to myself, but Satsuki wasn’t just my sister. The fact that I was currently ruining my underwear was evidence enough. I blew air through my nose and turned to whisper into Satsuki’s ear. 

I got distracted by the scent of her shampoo, but managed to get my message across. 

“I’ll behave if she will,” I frowned.

Satsuki nodded once, accepting my non-compromise. For the rest of the flight, Nonon thankfully was passed the fuck out, and I was able to talk to my sister quietly in peace. 

“Sats,” I caught her attention after a lull in our previous conversation. Her residual smile was still in place as she focused on me once more. I looked around me for coverage quickly before leaning back into her. 

“I’m sorry for being a pain,” I murmured to her shoulder, not meeting her eyes, “I get jealous of Nonon, ya know? And I get impatient. I just sort of pictured this summer as a little honeymoon or something, and now it sucks,” I flickered a glance to Satsuki’s gently relaxed eyes, “I love you,” I ended with a mumble. 

My sister was a giant sweetheart, and I fully expected the hand that crept under my blanket to hold my own. 

“Imouto,” she soothed, her fingers caressing mine. I relaxed. Her oceanic gaze sharpened, and she sent a similar scanning look around the cabin as I had. 

“Tomorrow night,” she hushed to me, “Before we leave for home, honey. We’ll have a honeymoon. Okay?” 

I grinned briefly and nodded, just in time for the Captain’s chime overhead to tell us to prepare to land. From the moment the wheels hit the tarmac to when we separated to change hotels the next night, Nonon was insufferable. Somehow, she had sniffed out that Satsuki had promised me something if I behaved, and she was determined to push the envelope. 

I was prepared to push her over a cliff. 

My sister kept her in line, but by way of capturing her attention. Which meant that I was devoid of it. Which sucked. But, what didn’t suck was the suite Satsuki had locked in for our honeymoon night. 

“Nee-san,” I breathed. Satsuki smirked at me. 

The place was fucking gorgeous. And huge. A full living room, a kitchen, mini bar, lounge area, full chrome plated bathroom, suite-style bedroom, and windows on one entire wall, floor to ceiling. 

I glanced at her with a raised eyebrow, “Who’s paying for this?” 

My sister’s eyes glinted a little more. 

“It’s a donation from the funds allocated to myself from many charitable persons,”

I snorted.

“All the underclassmen who want to fuck you are paying for this?”

Satsuki shrugged minutely, crossing to the kitchen and fetching a glass of water. 

“I had no use for their gifts, so exchanging them for real purpose shouldn’t harm their feelings in anyway,” her full lips twisted slightly behind her glass, “Spending those funds on my younger sister shouldn’t be a problem,”

I let my eyebrows furrow slightly, her wording bothering me somewhat. Her eyes, always so quick, caught the expression before I could clear it, but I turned away. I crossed to the lounge and observed the gaming set up. Shit, Xbox and PS4. Not bad. 

I jumped only slightly when my sister’s arms slid around me from behind, her gentle warmth enveloping my back. My ear tickled as she spoke into it, her cool tone settling in my heart. 

“Ryuuko,” she chanted, “What’s wrong, Imouto?” 

I bit my lip and twisted my head to meet her gentle ocean blue eyes. Those eyes flickered down to my lips, but she let me speak before she allowed herself to taste them. 

“I’m not just your little sister,” I started lowly. Satsuki frowned in confusion before her expression cleared, realizing her mistake. 

“Ryuuko,” she started, and I grit my teeth and turned in her arms, capturing her jaw in my hands.

“No, Satsuki,” I said sternly, a small ball of fire in my chest, “I know what you’re going to say. I’m your girlfriend. I know I am. But I don’t feel like your girlfriend. I feel like the pesky little tag along that Nonon just owned. All weekend, I’ve wanted to be here with you, just like this,” I huffed, trying to make Satsuki understand. 

“And I-,” my thoughts were wild. I didn’t know how to tell her what I was feeling. The short answer was ‘insecure’, but like hell would I admit to it, “I just want to, fuck, I just-“

She was trying to understand. Satsuki’s face was imploring me to continue speaking, but she just didn’t get it. So I stopped trying to tell her. 

When I pulled her face to mine, I felt the anger and fear ribboning my heart release. In this kiss, I found Satsuki’s lips, and I knew it was different. I knew she could feel it too. Because she gave a surprised sort of muffle, and then a deep-chested hum. 

In that moment, I knew exactly what I wanted. 

I gripped Satsuki by the hair and lead her towards the bedroom. A thrill echoed in my stomach, and traveled south to my dick. I guided her tongue with my own, and the resistance she offered me was at a 0. It was so fucking hot, to own Satsuki so completely. 

She stopped moving and I knew we were at the bed. Our kisses broke off as I gripped her shirt and aided her in taking it off. I stripped her, and then myself, and then we were naked on the bed together. 

I’ll never get over how good it feels to have Satsuki’s body, so long and lean, press into mine at every curvature. Her full breasts in my hands, her shapely ass and hips. God, she drove me crazy. Satsuki’s skin was absolutely flawless, pulled taut on her stomach, interrupted only by her hardened cock, straining in lust. 

I’m not going to lie, I teased her. I was half out of my mind with want, but for some reason, I felt so in control. This was about Satsuki. My Satsuki. I kissed and licked at her neck, massaging her thighs and ass. She was moaning and running her fingers though my hair as I topped her, her full lips red, and her face set in an adorably sexy flush.

My dick was throbbing. The heat from her was overwhelming, and even bumping into that soft spot sent my head reeling in pleasure. 

“Ryuuko,” my sister called, her voice a broken sort of asking. I smirked, my face in her neck. 

Currently, I was running my cock through her deliciously wet folds, refusing to press any harder. My hands held her hamstrings, and the muscles were spasming as Satsuki spread her legs without thinking about it. 

In reality, it was the sluttiest I’d ever seen my sister. On her back in a hotel room, panting and pleading for me. God, she’s beautiful. 

“Nee-san,” I huffed, losing control of my hips’ smooth motion. Her hands gripped my back. 

“Please, Ryuuko?” she nearly whined, “Be careful, baby,”

I nodded. Taking a hand off her creamy thigh to grip my dick, I realized she was right. We’d never done this before, and I was actually pretty thick. Still, Sats was plenty wet.

“Ready?” I grunted, guiding my slick shaft to the softest spot on my sister’s vagina. 

“Yes,” her voice was shaky, and my heart melted. 

I pushed. 

“Fucking God,” I moaned, fisting Satsuki’s hair in one hand, gripping the bed with the other. Satsuki’s breathing had sped up considerably, and she practically clawed at my back.

She was so warm inside. Like liquid heat, but so tightly wrapped around my sensitive dick. I instantly wanted to start moving, because that heat was spreadable, that friction would feel so good. 

“Nee-san,” I whined, “You’re so incredible. Satsuki,” I was almost begging and I didn’t know why. It wasn’t until I felt the pressure of her calves on my hips that I realized she could take more. 

So I moved. Deeper and deeper, and I felt Satsuki clenching and unclenching around my dick. I found myself seconds away from coming and I was desperate to hold off. 

Finally, my hips pushed flush to her thighs, and I glanced down, breathless, to see Satsuki’s insides had taken my entire cock. I swallowed, and closed my eyes. She was so hot and tight, I knew I could come without moving a muscle.

“Ryuuko,” Satsuki cooed, and I felt one of her hands slip into my hair. Opening my eyes, I was met with her beautifully tender expression. She brought me down for a kiss, and I complied. I felt her gently push me until my back was against the soft sheet, and she straightened. 

Not wasting a second, Satsuki settled her weight on her shins and drew herself up. My eyes widened as I watched her expression flicker and then twist in ecstasy when she dropped back down. 

The friction was so amazing. Satsuki set a gentle, loving pace, and I didn’t want anything different. My hands stroked her creamy things, and gripped at her firm ass, watching her cock bounce with her. 

“Nee-san,” I breathed, and Satsuki’s lust filled blue eyes flashed, “Nee-san, talk to me,” I begged. 

My dick was so hard, and she was riding me so deeply, her insides velvet fire. 

“Ryuuko,” Satsuki strained, her voice sounding like rich smoke, “You feel so good inside me. Your cock is so big, I can’t help myself,”  
I whimpered. 

I felt like my cock was granite inside my sister, and it was only getting harder. My balls were tight and I knew I could come, just like this. I shut my eyes and whined deep in my throat. I wanted so badly to be selfish. 

“Nee-sama,” it tore from me without my consent, but the ripple of Satsuki’s inner muscles made me want to scream. She was so hot inside. A small, choked whimper made me open my eyes, and I moaned. 

Satsuki was riding my cock, our juices pooled together on my stomach, and jerking herself off in sure, smooth strokes. 

“Sats-“ I begged my sister. She locked eyes with me, and I knew she would have mercy on me. Her delicious body bent forward, the hand not on her cock supporting her weight. Then, she held completely still, touching my lips sweetly before moving to lick at my ear.

I instantly took over.

I pumped in and out of my sister, and the breath drove out of my lungs. I plunged into her liquid heat with love and reverence. Finally, finally, I felt Satsuki stiffen, and a hot jet of what I knew to be her cum landed over my stomach. Her insides squeezed me to suffocation, and I let go completely. 

I don’t even remember what happened, because I think I honest to God blacked out a little bit. But when I came to, I was aching between my legs, and my dick was still hard, but considerably more wet than before. 

Satsuki lay on her stomach next to me, breathing, and peppering kisses to my shoulder, her eyes wonderfully clear.

“Satsuki,” I breathed heavily, looking over at my sister. I swallowed, “I’m not gonna lie. Fucking you was the best thing in the world, it was,” Apparently my face was telling quicker than my words, because Satsuki’s eyes clouded over with something so deliciously arrogant.

“But,” I bit my lip and tried not to sound like I was begging, “I really need you to fuck me now, Nee-sama,”

Satsuki didn’t waste a second. 

In a flash, she had pulled herself up and flipped to kneel between my legs, pulling on my hips. I immediately complied, rising to all fours. A shiver made it’s way down my spine. 

I felt one of her hand between my shoulder blades, and I yielded to her firm direction, lowering my chest to the mattress. My ass was high in the air, my hands clenched to fists inside the hollow of my throat. It was the supreme submissive pose, and I loved it. 

“Imouto,” Satsuki purred from behind me. 

I tried to twist to see her, but her hand was strongly holding me down. 

“Yeah, Sats?” On my back, her fingers curled to press her nails warningly into my skin. I smiled, “Nee-san?” I tried.

“That’s right,” she whispered, and my dick hardened when I felt her push a single digit into my depths. Good God, how I wanted so much more, “I’m your onee-san, and Ryuuko, I love you more than anything,” 

I whined as I listened. She was stirring me deeply, the gentlest feeling of being toyed with. I was so wet I could hear her finger squelching my juices. 

“I want you to know, I’ll always love you,” Satsuki continued gently. She pulled out to massage my balls, “I’ll always take care of you,” she pushed what felt like two fingers inside and I groaned. 

“But first,” she hummed, “I’m going to make you feel good, my love,” she pulled out, and I felt the bed dip as she readjusted herself. I quivered in anticipation, my stomach roiling, and my vagina throbbing, “I promise you’ll feel good,” Satsuki completed, her hand trailing from my back to hold my hip, “Don’t hate me,”

And then all eight inches of Satsuki were slammed inside me. Instantly, I shot up to my elbows and howled in surprise and a bit of pain, but my sister was quicker. She leaned her full weight into pushing my shoulders back down, while she plowed into me. 

We had had rough sex before, my sister and I, but not like this. This time, I felt like I was actually being fucked. Truly fucked. It was brutal, how hard Satsuki was ramming me at this angle. I had never been in this position before, and it was the deepest penetration I’d ever had. Keeping in mind the fact that Satsuki was eight fucking inches and decently wide, my sister was sliding against every wall inside me, and bottoming out as she savagely hit the top of my cervix. 

And I could not stop screaming. 

It was clear why my sister was always on top.

It was amazing. Satsuki had leaned back and used her hands to spread my ass and legs apart, leaving the way clear for her to enter me as much as possible. Her dick was so perfect inside me. The angle of my legs had my internal muscles tightening the channel of my body, and her girth was just enough to be a little too tight. It was delicious. 

I felt owned, and dominated, and loved, all at once. Satsuki was claiming me as hers. As the one she wanted, needed, had to have, and no one else was good enough. She was making me feel like I was the one person who could make her feel like this.

And it was great.

She spanked me, and I yelled. The sting was so pleasant. My body was absolutely singing in ecstasy, and Satsuki showed no sign of slowing. Mechanically, she was pounding into me. Like some steam-powered metronome, my sister was railing me, her dick hard as granite and soaking in precum and my own lubricating liquids. The slap of our skin together was obscene, and the frantic creaking of the bed only added to it. 

It was only a matter of time before I came. And I felt it pooling deep inside me. Every withdraw and pound my sister delivered to me was a ratchet up in winding the coil of my orgasm. 

I gave short screams in time with her pounding, and I was losing my mind, coherent thought flying out the window. I only knew two things.

“So. Good!”

And

“Nee! Sa! Ma!” 

Also some swear words. 

But Satsuki wanted more. The strain in her voice was evident, and it sounded like she was in some blissful sort of agony. 

“I love you,” she wailed deeply.

“Ah! Love you,” I mimicked, near tears. My orgasm was so, so close. 

“Come for me,” she purred in stress. 

I re-fisted my grip on the sheets and let the veritable volcano of my orgasm erupt within me. Before I knew it, I had clamped down on Satsuki’s cock and shook from top to toe, holding my breath as I came.


	4. Chapter 4

**Notes for the Chapter:**

> This is from Ryuuko's perspective. It was more important for the "plot progression".

I was nervous as fuck.  
But this was my plan and I didn’t intend to give up now. I pulled a breath in and let it out smoothly.  
Right.  
I pulled another breath in and went to find my sister. As usual, she was sitting in the study, pouring over her already completed homework. I smiled slightly at her back. 

She really was so fucking cute.  
“Nee-san,” I sang softly, sliding my arms around her neck in a hug. I nuzzled into her hair and pulled her scent into my being, relaxing to the core, “Come take a break with your imouto,” I pled, glancing a kiss to her cheek.  
I felt her body, so tense in her concentration, immediately sigh in relief as she leaned back in unwinding ease. She brought a hand to stroke my forearms gently and she let out a chuckle.  
“Funny, how my imouto seems to have already been taking a break. An entire day’s worth of a break. Right, Ryuuko?” she hummed.  
I grinned, burying my face in her neck and shoulder joint.  
“I need a rest from all my rest, babe,” I laid a lick and nip to her ear in punctuation, and I watched in delight as her left hand twitched around her pencil. That’s a good sign.  
Come on, Ryuuko, you can do this.  
Satsuki chuckled, leaning away from me to get me to release her. She spun her chair around and I obediently climbed into her lap, straddling her. Satsuki leaned up with a smile, and I met her through a happy kiss.  
“Why does it sound like you’re spelling ‘rest’, ‘s-e-x’? Hm?”  
I laughed, carding my fingers through Satsuki’s silken locks. She let me kiss her again, and I cheekily bit her lip lightly, smoothing my tongue over it. I played with her hair gently, and couldn’t help but kiss her soft lips again.  
“I’m getting jealous of your notecards,” I teased, rubbing her nose with mine, “You clearly love them more than me,”  
Satsuki laughed, and my spine softened. I loved her laughter. I loved that she only laughed like this with me. My resolve tightened. I can do this.  
“I wouldn’t want you getting that idea, Imouto,” she murmured against my lips. I smiled, and she laid a kiss on me sensually. I opened my mouth slightly to let her tongue swipe mine gently, pressing our lips together in a perfect match.  
I hummed deep in my chest without thinking about it. I loved being close to Satsuki. With Satsuki. I smiled when I felt her hands slip under my thighs tightly, and she didn’t let me ruin the kiss with my laugh. She merely stood up, taking me with her.  
We kept kissing as I wrapped my legs around her hips. My dick stirred in my jean shorts as she moved to walk us out of the study, and I grew more excited with ever step she took. I broke back from her lips.  
“I bought condoms,” I graveled out, and Satsuki raised an eyebrow interestedly.  
“Did we run out, or are we trying something new?”  
I grinned fully.  
“Ultra Thins from Trojan,” I purred, tracing her bottom lip with mine. Satsuki hummed deeply in subdued enthusiasm, “In my room, babe,”  
She turned to carry me to my rarely-used bedroom, and I grinned. I broke away from her to strip my own shirt off and Satsuki raised a pleased eyebrow. I smiled cockily and rolled my sports bra off of me as well, and the next thing I knew, I was being pushed against my bedroom’s door, and my heart rate spiked.  
Satsuki set me down and I scratched at her shirt until she pulled it off. I helped her with her jeans, and they slid down her beautifully toned legs. I felt behind me and opened the door, almost falling through it from my sister’s hands on my chest.  
Shutting it behind her, I shivered and smiled at the hungry look in her eyes. Accepting the challenge, I met her in a devouring kiss and she embraced me fully as I knotted her hair.  
An exhaled groan alerted me to the fact that I had started grinding on my sister, and I looked down to admire her growing erection. In the moment I wasn’t busy, Satsuki all but tackled me to the bed.  
“You or me?” she growled into my ear, and I felt my shorts loosen as she unbuttoned and lowered the zipper to them. I kissed her cheek and jaw above me.  
“You,” I rusked, and my chest gave a thump at the deeply pleased look in Satsuki’s eyes. She pretended to think as she sat up and pulled my shorts and underwear down and off me. Her eyes admired my hard cock springing out of the removed items.  
“What do we say when we want things, Imouto?”  
I rolled my eyes, and narrowed them at her. Without a word, I reached over to grab a pillow and shove it under my butt, lifting my hips significantly. Spreading my legs, I made a perfect wide V, my hands going to my calves to keep my flexibility shown off.  
Satsuki licked her lips, her eyes locked between my spread legs.  
“That will suffice,” she said throatily.  
I sent her a challenging grin.  
“You gonna stare or come fuck me?”  
Satsuki’s eyes flicked up to me, and her expression hardened. So did her dick. Her fingers were so fucking nimble. She unclasped her bra, stepped out of her panties and reached for my desk behind her in the same second. I bit my lip in anticipation as she ripped open a condom and rolled it over her straining length hurriedly.  
“Nee-san,” I chanted softly, devilishly.  
“Ryuuko,” Satsuki said in answer, her perfect breasts heavy and rolling as she slowly climbed from the foot of the bed toward me, “I love you, honey, so very much,”  
My stomach fluttered, and my abs and insides tightened. My dick was already feeling pressurized, my semen roiling in my balls.  
“I love you more than life itself,” Satsuki continued, reaching me and fixing herself to kneel on her knees, her back straight, “But today, I think I’ll fuck you,”  
Her low, smoking voice filtered through my head and I smiled through my bitten lip as her hands strongly clasped around my lower quads, right above my knees. Her musculature was on perfect display, her arms keeping my legs far apart, and her shoulders and trapezius flexed. I nearly jumped as her erection slid through my folds, and she smirked sexily.  
“Oh yeah? I asked, reaching to hold her wrists.  
“Mhmm,” she hummed her eyes drifting to her twitching dick and my soaked slit.  
“Show me,”  
Her slide inside me nearly made me come.  
“Jesus, fuck, you feel so good, Nee-sama,” I whined, throwing my head back. I hear Satsuki growl in her chest, her abs flexing as she pulled her hips back, pulling out. I groaned.  
“I like these ones, Imouto,” Satsuki said, pushing back in solidly and slickly. I felt myself shiver from the inside out, “I like them a lot,” she moaned, her breasts bouncing as her pace sped, “Oh, Ryuuko, you feel good,”  
I loved feeling her inside me. My sister was so big, every time. I was addicted to my body’s own intolerance to her size. Satsuki started to huff, her dominant position strenuous. But every force of her cock inside me was angled against the front of my vagina, and I felt myself coiling up and up and up.  
“Nee-sama,” I begged, one of my hands finding my own dick, the other into my hair and clenching, “Nee-sama, please,”  
Satsuki kept her pace, not changing her steadily heavy fucking. Her thrusts were perfect; fast and forceful, with the delicious wet slapping of both our juices. It felt like a steam engine was pounding into me. My hand wrapped around my own length and jerked in quick time.  
“Nee-sama,” my eyes were clenched shut, “Fuck, don’t stop! Fuck,”  
“Ryuuko, come, honey,” Satsuki growled, and I obeyed her with worshipful submission.  
My toes curled as my thighs shook and I let my orgasm roll through me. My muscles, every single one, flexed in ecstasy. My entire being was focused on the hot clenching my insides were doing, as Satsuki’s solid dick impaled me, and I only faintly recognized the tingle of hot cum on my stomach and tits as I came on myself.  
Satsuki gave a long, loud, gasping groan, and her nails dug deeply into my calves. I gave a rasping inhale as I came down from my high. My sister panted and pulled out, sliding to lie next to me. I ripped the pillow out from under me and finally relaxed the lower half of my body on the bed.  
I gave a long, satisfied hum and watched Satsuki as she removed her cum-filled condom and tied it off, placing it on the far side of the bed before rolling to face me. I grinned, rolling as well, and she smiled back, kissing me lightly.  
“That was wonderful, honey,” she murmured, closing her eyes, “Thank you,”  
I laughed, “Stop that,” I feigned a light slap at her, “I don’t like it when you thank me,” my sister smiled but nodded.  
“I’m glad you liked those condoms,” I started, my nervousness mounting once more, but Satsuki merely purred, totally content.  
“Like the real thing?” I asked, and she hummed noncommittally.  
“Almost,” she said.  
“You like going without them better?”  
“Of course,”  
I swallowed, a hint of my nerves peeking through, “You could go without them, if you wanted,”  
“Birth control would be bad for you, Imouto,” her voice was still level, but a little more alert.  
“I know,” I said, taking in her still features. I bit my lip, “There’s a better method, though, if we wanted to make sure you’d never put your bun in my oven,”  
Satsuki’s body stilled, and my heart rate picked up.  
“Oh? And what are you suggesting, Ryuuko?”  
I swallowed again.  
“We could have you get a v-vasectomy?”  
I felt a little lightheaded, and I watched as Satsuki finally opened her eyes to stare at me. The same eyes I had. She blinked, and her face went from peaceful to conflicted focus. Satsuki propped herself on an elbow slowly, her hair falling like a silken wave of ebony over her shoulder. She looked down on me with a confused frown.  
“You want me to get a vasectomy?”  
I winced internally.  
“Only if you want to, Sats!” I sat up, pulling a pillow into my lap self consciously, “I just- I know you miss coming inside me,” I ran a hand through my hair, “And I know you hate condoms. And to be honest, I miss you coming in me, too. It felt so incredible. I mean, it’d be nice to not have to worry about protection or anything, and we both know we could never have a kid. So… it was just a thought,”  
I knotted my fingers together and watched her intently. Satsuki brought a hand to rub her face.  
“Ryuuko, I-“ she broke off, and sighed. Her eyes met mine and her posture seemed to soften, “I’ll think about it, okay?”  
I smiled, relieved she wasn’t mad or anything.  
“’Kay,” I shrugged, jumping out of bed, “I’ve got my cum on me, so I’m going to shower,” I cast a frown to my sister in bed, and she raised a brow. I grinned, “I could have your cum on me too, but… condoms. You coming?”  
I barely dodged the pillow Satsuki threw at me, and I laughed my way to the bathroom.  
Phase one, complete.  
About an hour later, after my sister and I had eaten, and she had gone back to studying, I returned to my room and took another breath. Reaching to my desk, I flipped over a thick pile of papers covering two small stacks of books. I smiled, and retrieved the camcorder. I shut the blinking red light off and did the same to the other camera on the shelf of my headboard.  
Oh yes.  
I instantly ejected both memory cards and grabbed the necessary cords and headphones required for my future work and jumped onto my computer. I was so excited, my hands shook as I shoved all the things in the right slots and waited for the videos to upload from each card.  
On a whim, I clicked one to open it and waited. At first, nothing happened, but the clear picture of my bed was visible, pointing toward the foot. I had very scientifically laid in bed before hand and ensured it would point to where I wanted.  
Skipping forward, I let the mouse hover over thirteen minutes into the video and released. My jaw dropped.  
My sister was pounding into me, her abs clenched, her face swimming in ecstasy and adoration, relief and strain flexing across her features. She held my legs far apart and was audibly groaning. And I watched, eyes wide, as I was lying beneath her, and taking every inch of her dick disappearing into me, whining and moaning in twists of my face, my eyes flickering closed.  
Holy. Fucking. Shit.  
I couldn’t help what I did next. It was instinct and need and greedy, clumsy lust, all rolled into one enormous ball of a horny lack of self-control.  
I jerked off.  
I paused the video, and focused on the frame. Despite my eagerness, I didn’t want to unwrap my present to myself too quickly. So I grabbed my hardened dick like it was going somewhere and went to town.  
My eyes were locked on the screen, and seeing Satsuki’s wonderful nakedness, hardness, and passionate eyes, I knew it had worked. My bicep started to tingle in exertion, but my cock was in heaven. I wristed my wrist the way Satsuki does to me, and felt my insides buckle in pleasure.  
When I came, I actually came.  
I had never come without Satsuki present, and it seemed my libido accepted virtual Satsuki as a poor substitute. But I only sat on my bed, my hand and shirt covered in cum, laughing in relief. Even as I washed my hands and changed, I was smiling in delight.  
Phase three would go so much more smoothly now.  
I managed to edit the two videos without beating off, and the end result was a decent mother fucking porno. Things that were homemade made all the difference. With the completion of the video, Phase two was complete.  
I had to wait almost an entire week until Phase three could begin, and I knew this would be the most difficult part. But I had to see it through. I had faith it would all work out. So when Satsuki had told me that morning she had to attend some Student Council meeting for the region’s high school something or another, I saw my first chance.  
I had driven myself to school, but when it let out, I had texted her to ask if I could come say goodbye to her. My answer told me she was in the SC office, and I jogged there.  
“I’ll probably be home late,” she said after I leaned to kiss her, and I nodded.  
“You gonna eat out there?”  
Satsuki had nodded, “Most likely, Imouto. No need to wait up for me, but please accomplish your homework,”  
I rolled my eyes and waved, leaving for the day with a final kiss goodbye. I sped home. I felt a little dirty, but it wasn’t like I was lying to her. I just wasn’t telling her about her birthday present.  
My room was only ever used when I was doing something I didn’t want Satsuki to know about. Or as I called it, ‘gaming’. She was intelligent enough to put together that it was ‘my’ space, and sometimes I liked to be left alone. Satsuki was so good to me, and I loved her so much for it. I tried to be as respectful to her, and I think she noticed when I started to let her be when the study doors were shut.  
Hunkering down under my bed, I felt around until my fingers brushed a shoebox and my computer. I pulled it open and with both things on the bed, my body started to hum. I opened my laptop and re-opened a browser page I had frequented in my research and re-read carefully.  
Right. Let’s go.  
I jumped in the shower and rinsed off. Carefully, I let my hand travel down my body and round my own ass. I brushed my entrance but reached around to the usual exit.  
And slid a finger in.  
It was the weirdest sensation in the world, but I was happy to find out it wasn’t bad. I had emptied my bowels earlier today as instructed, but the internet said this was a necessary step for maximum cleanliness. I wanted Satsuki to be totally comfortable.  
Gingerly, I wiggled my finger around in my butt, and rinsed my hand in the shower’s spray every so often. The tissue there wasn’t as soft as inside my vagina, but it was still pretty warm and nice. The best thing about it was feeling the rigid ring of muscles around my finger adjust around the digit.  
The need for a lot of lube suddenly made sense in my head, as the pushing and pulling out on the sphincter was what made this feel so good, and an uncomfortable hot friction built up almost immediately. Satisfied that my insides were clean, I dried off and made my way back to the bed. I laid the towel down as an after thought.  
Never too careful.  
I flipped the top of the box open and stared down at my fate. Reaching inside, I took out the red dildo and bottle of lube, gritting my teeth.  
It had all started when Nonon, the little shit, had once called me a tight ass. I was off my game that day, so I growled and snapped at her and she had been delighted as she realized she had gotten to me.  
It snowballed from there.  
So for my birthday, she had gifted me on the side with this little number. The attached note had read, ‘go fuck yourself’. Still, she had been kind enough to even throw in some lube. I kind of hated that I was actually going to use it.  
Still, it was all for Satsuki. And kind of for me. But I knew that this stage had to be done by myself. The hard, painful, awkward part. Firstly, because my pride would probably never let Satsuki see me uncomfortable or whatever was about to happen, and secondly, because my sister would never, ever, want to hurt me. Even like this.  
So it was up to me, and I was determined to see it through with a soldier-like sense of duty. I started to get set up. I sat on my knees in bed, and uncapped the lube, pouring a generous amount on the toy and spreading it around with my hand. The dildo itself was smaller than Satsuki, something that could be a problem, but the girth of it was pretty similar. It was such an innocent sort of device, and I silently apologized to it.  
But it had to be done. I poured another helping of lube onto my hand and breathed. I leaned forward to rest my head on my fist, my forearm and knees on the bed.  
Experimentally, I reached back and spread the lube around my asshole. Massaging and rubbing, and I eventually gave in and started to enjoy the feelings I was inflicting on myself. My fingers were drenched in lube, and I took another deep breath before slipping a finger inside, and I immediately clenched around it.  
Fuck. Gotta relax.  
I rubbed around and twisted, getting used to the sensation. My dick was even plumping up, like it was interested in the goings on. I focused on relaxing as I took my second finger, and slowly pressed it next to my first.  
Relax, relax, relax, relax.  
When I made it, I paused, and ignored the spastic fluttering of my butthole on my knuckles. It took a while, but I eventually got to the point where I could twist my wrist and scissor my fingers inside. I resisted the urge to bear down and push, but I eventually extracted my hand from my ass.  
Without anything in it, my butt felt odd as fuck. Like there was supposed to be something in there now.  
I supposed I’d have to oblige it.  
The red dildo was still sopping with lube, and I swallowed. Reaching around, I dragged the toy through my folds, and circled the head around my slightly softened butt.  
Pressing lightly, I knew this wasn’t going to go over very smoothly. But I persevered. I pushed harder, and I felt my asshole give way, and the head stretched me to breaking as I pressed. I gave a cry and removed it, breathing hard. A moment, and I tried again. The pressure was insane, and I grit my teeth with a sob in my throat as the head penetrated my butt. Desperately, I poured more lube on my ass, and the cold trickle of it made me hard.  
But eventually, I did it.  
After the first inch, it was merely a matter of pushing the rest in, and the lubrication was life saving. I waited almost five entire minutes for my sphincter to relax and adjust. Still, I was proud of myself. If I could take a dildo in the ass, I could take Satsuki.  
I think it’s safe to say the first few pushes and pulls were awkward. Painful, strange, and awkward. I reached my clean hand to tap my laptop, and the sex tape of my sister and I started playing.  
Simultaneously, I was horrified and ridiculously excited to see how hard Satsuki was banging me. Imagining that forceful, sexy thrusting in my full, stretched ass made me hard as a rock. I kept my eyes on the screen, and continued to fuck my ass with the toy.  
After a daring thrust, my entire body felt a shock. I had just pushed the full length inside me, and what must have been the head brushed a spot inside that made my dick jump in pleasure.  
My prostate.  
Oh, fuck.  
It was my first time doing it, but I was comfortable enough to try to chase an orgasm. The dildo, though, wasn’t long enough to help me. I wiggled about and tried to reach, but it wasn’t happening.  
I’d bet anything, though. My sister could hit it.  
In the end, I wound up with my face pressed against the bed, jerking off with one hand, and fucking myself with the other, my ear tuned to the wonderful slaps and moans of past Satsuki and I having sex.  
I came slowly and softly, shooting cum on the towel under me, and I stopped to breathe harshly.  
Okay. Not bad.  
The clean up wasn’t terrible. I had prepped pretty well, and everything was nice and sterile as I removed my hands and dildo from their places. Sterile, but absolutely fucking covered in lube. And I’m sure I would have to try and get rid of all the lube that was currently inside me.  
But aside from that, the only thing was that I was sore as hell. Specifically, my asshole. I didn’t want to move or bend or even wipe the damned thing.  
Eventually, all the evidence from the beginning of Phase three was cleaned and stored away, and I crawled into Satsuki’s bed feeling weird. My butt was so sensitive and sore, and I couldn’t help the feeling that Satsuki would know.  
Would she be mad? Was it cheating? I couldn’t possibly cheat on she with myself, right? Wait, did Satsuki masturbate?  
Fuck.  
I tried my best to just relax and focus on going to sleep, and a couple hours of tossing and turning got me there. I woke up in the middle of the night to feel my sister’s warm arms wrap around my middle and drag me back into her chest, and I gave a drowsy hum of contentment.  
Yeah, this is what I was missing.  
I smiled but murmured out, “Love you, Nee-san,”  
Satsuki squeezed me lightly, nuzzling my neck.  
“I love you too, Imouto. Now go back to sleep,”  
I closed my eyes and did just that.  
When the sun shone through my sister’s window the next morning, I gave a sleepy stretch and a moan of satisfaction. It was the weekend, and Satsuki had let me sleep in. 

Let herself sleep in, too, apparently. Her warmth was so, so nice in bed, and I felt her hand gently rubbing my flat stomach, just the space between my ribs. She’s been doing it since we were kids, and it never failed to relax me.  
It sort of made me feel like a dog getting its belly scratched, but I honestly didn’t care. I would have wagged my tail if I had one – it just felt nice.  
I smiled instead, and wiggled backwards to press more fully into Satsuki. The motion caused me to feel a pleasing sort of soreness coming from my butt, but it wasn’t too distracting.  
“Mornin, Sats,”  
“Good morning, Imouto,” she whispered into my ear, adjusting to receive the curve of my body most accurately. Her morning wood found its way between my butt cheeks, and I made myself lie still instead of jumping.  
Satsuki leaned and buried her face in my hair, inhaling. She laid a kiss to my locks, and I smiled some more. My sister was just the best, most loving and cuddly thing.  
“What time did you get home last night?” I asked interestedly, and Satsuki hummed into my neck.  
“Somewhere around 2,”  
“Whoa. What the hell for?”  
Her chest rumbled on my back as her tone turned towards displeased.  
“Uzu and Nonon insisted we have a drink after the long meeting. I tried to tell them I would bow out, but they insisted that if I weren’t there, it wasn’t worth doing. I didn’t want to be rude,”  
I scrunched my nose.  
“I missed you last night,” and I had. I had imagined her fucking me in the ass last night, a little wanton lust still lingering in my heart from the fantasy.  
“Oh?” Satsuki said, her voice pitching to the familiar velvet. My mind ground to a halt as she pressed her hips a little firmed into me, her lips dipping and nipping at my ear.  
Shit. Shit shit shit shit.  
“How much did you miss me?” she asked lowly, her tone sweet in its darkness. She slipped her hand over my stomach to dip into my boxers, and my dick jumped with an electric current as she gripped the semi-solid erection.  
“A lot,” I breathed measuredly. I tried to think. There is no way I was letting Satsuki put her dick in me. No fucking way. Even thinking about her length, delicious and sexy as it was, going inside any orifice down there made me hurt.  
“Hmm,” she continued, dancing her fingertips over the head of my penis, “I’m sorry I’ve been busy this week, honey,” she kissed my cheek, “I promise I’ll make it up to you,”  
I nearly groaned aloud. Satsuki was being sweet, and she was horny and happy, and I didn’t blame her. We usually had sex whenever we wanted throughout the weekend, so her behavior wasn’t weird in the slightest. But I had shoved a dildo up my asshole last night and come. I was good for at least another day.  
But all my sister knew was that the last time either of us had enjoyed an orgasm together was Tuesday. It’s fucking Saturday. Knowing Satsuki, she’d be attentive and wonderfully loving, playful and seductively charismatic. She might even let me go inside her.  
I was screwed. Suddenly, I got an idea. I turned over in her arms, and she looked at me, a little surprised. I was usually more than happy to enjoy an early-morning handjob.  
“A lot, Nee-sama,” I smirked, kissing her quickly on the lips. Then, I ducked under the covers and disappeared from her line of sight.  
“Ryuuko-“ Satsuki bit off, but I was already positioned between her legs. I pawed frantically at her pajama pants, and I think she was too shocked to lift her hips.  
Ah well, guess I’d have to hold the hem down myself. It’d make me work my mouth more without the aide of my hands, but that could be fun, I guess.  
Her erection sprang free, not quite fully hard, but on the way. I latched my mouth onto the head and let my saliva spill all around it. Above me, Satsuki gave a great shuddering sigh, and I felt the weight of her hands through the covers on each side of my head.  
I lapped at the head for a fair bit with my tongue the way that gets Satsuki hard, and then I pulled a deep breath through my nose. Sinking down her impressive length, I had to readjust my lips every few inches. As I neared the last couple, I bobbed up for another breath and kept working at it.  
By now, she was hard as a rock, and her dick was threatening to choke me. But I had a goal. I eventually kept a cool head enough to relax my throat and think about how hot my sister was that I broke the barrier in my throat, past my gag reflex.  
I stayed down, nuzzling with my nose the incredibly neat crop of soft black pubic hair I had requested my sister groom. For this exact reason. This, and I thought it was hot when she got cum on it.  
“Oh, Imouto,” she breathed, trying hard not to squirm, her quads seizing instead.  
I pulled all the way up and bobbed on her head a couple times before sinking all the way back down, resisting the urge to swallow away the thick coat of saliva and precum that gave me some lubrication. Her hair tickled my nose, and I loved every second of it.  
I flexed my throat in almost a rhythm, and Satsuki gave a small groan. After that movement, I felt my eyes water and I had to pull back up for air. Under the blanket, the air was humid and sticky, and I loved the visual of her drenched, proud cock standing in wait for me to make her come.  
An idea occurred to me, and I gave her shaft a few lubricating licks, going back to suck on her head. Satsuki whined, and I grinned. I honestly loved doing this. It was such a fucking power trip.  
I brought the tip back to my lips and unhinged my jaw to force her dick down my throat, shaking my head a little as my nose dug into her public hair. Quickly, I switched my hands to hold her pants down with one hand and reached my right to my own throat.  
I could feel the bulge of her sizable dick in my windpipe, and I pressed harder on the obstruction with my fingertips spread down the length. Hopefully, she’d be able to feel it.  
“Ryuuko!” Satsuki shouted, startled. Before just this moment, I didn’t know it was possible to startle someone into orgasm, but it sure as shit is.  
A single one of her hands clamped down on my head and she released an enormous moan that I recognized with glee. More familiar, though, was the jetting of her cum down my throat.  
Frantically, I pushed against her hand. She let me have autonomy back, and I pulled to the head of her cock, my hand leaving my throat to jerk her off. Satsuki hadn’t come in five entire days. I usually got her off every other day at worst, twice a day at best, and every day on average. But like fuck was I going to waste a build up of five days of cum by letting her blow her load down my throat.  
I gave her pressure and a flutter of my tongue on her head, and she absolutely poured into my mouth.  
It was my turn to be a little shocked. My sister usually came in two spurts, maybe three. They were thick ropes, and she always had a pause between each that gave her the pressure to shoot from my vagina to my face when she pulled out.  
But this time, she came not twice. Not three times. Not even four. Five. Satsuki shot so many streams of cum, I had half a mind to take my mouth off and watch her. But that wasn’t all. They were one after the other. Rapid fire.  
Her cum was always thick and creamy, so hot it burned as it erupted from her balls. I was addicted to that scorch against the back of my throat and on my tongue.  
I didn’t fucking care if that made me a real life cum slut. My sister’s diet was so goddamn balanced. She hated fried anything, and her honest to God favorite food is apples. Her cum tastes like thick, sweet, coconut water, with a hint of sugar. I loved it.  
So when she quite literally blew a mouthful, I was shocked and so goddamn excited. Five powerful gushes of that, and I squeezed her to get all of it. While she did it, more than a little had overflowed my mouth and run down the corners of my lips.  
I found my mouth’s added heat contrast sharply as Satsuki ripped the blanket from my head and her eyes were the heaviest of storms.  
“Open,” she demanded, her voice rough.  
I knew she’d be mad if I swallowed any, and I decided I’ve had a good enough taste. So I obeyed her command, and opened my mouth slightly, letting her see the veritable bath of cum she had just fed me. Her eyes took an iron, focused edge, and she gripped my hair in her fingers and pulled slightly, my head tilting back.  
“Swallow,” she hushed, and I obliged more than willingly. Delicious. Even more delicious was the look of satisfaction in Satsuki’s eyes, and I smiled. It took me two entire good, long, bobs of my throat to take all of her cum.  
Her stormy blue eyes were turning gentler by the second, and she smiled as she pulled me by the neck up to her. Satsuki’s free hand came up to wipe the leaked cum from the corners of my mouth, and she fed the digits to me.  
And fuck yes, I acted like that was a treat.  
When we finally rolled out of bed, Satsuki showered and I made a quick, simple breakfast. My sister sweetly ate everything I had prepared for her, and we spent all of Saturday cuddled together, watching movies.  
Of course, the problem with this was Satsuki. As in, for once, it wasn’t me. And it was weird. I wasn’t used to not wanting my sister to fuck me, and Satsuki thought I was being just as strange.  
She played it cool, though, and gave me my space. But when my abstinence lasted into Sunday night, she cracked as carefully as she could manage.  
“Ryuuko,” my sister started carefully, watching me put actual clothes on to sleep in. She was already lying in bed, a thin nightie barely covering her.  
“Yeah?” I tried to be just as calm.  
“Have I.. done something?”  
I internally winced. Of course she’d think it was her. I flashed her a frown, playing stupid.  
“What do you mean?”  
She seemed to expect this, and her nimble fingers traced circles in the comforter as she considered her wording. Her eyebrows were lowered in thought, and I climbed into bed quickly, trying desperately to beat her brilliant mind.  
“I suppose after a few months, it’s only natural,” she mumbled to herself, and I felt a little bit of hope, mixed with a fuckton of guilt. Satsuki thought I was getting bored of her.  
Sexually, bored of her. I didn’t even know where to start on how wrong she was.  
“What?” I asked like I hadn’t heard her.  
Satsuki cleared her throat, “Nothing. Are you tired, Imouto?”  
I licked my lips and nodded. She immediately turned to shut the bedside lamp off, and I curled into her to sleep for the night, hoping to God I was doing the right thing.  
I tried to time it right, I really did, but my sister made me such a priority in her life, we were rarely apart when separation wasn’t forced on us. So I when Satsuki was gone, I was in training.  
As in, I was fucking myself in the ass with a red plastic dildo while I watched homemade porn.  
Which was unfortunate, because in the first two weeks, I had managed it twice. And was sore as hell for the next four days, almost. Meaning my sister had gotten a lot of head.  
Which, knowing Satsuki’s particular kinks and preferences, was a problem. Because my sister fucking loved being inside me. Hell, I fucking loved it when my sister was inside me. But there was no way to get around the fact that Satsuki was getting confused, and a touch insecure.

**Notes for the Chapter:**

> And so, Ryuuko schemes.


	5. Chapter 5

I loved my sister. Truly, more than the average amount allowed in most societies. I loved Ryuuko, and I tried my best to show her. I went out of my way to attend to her needs, and it gave me pleasure to answer her wants as well. I made sure she was paid attention to, did everything in my considerable power to ensure she was comfortable, and showed respect to her space. 

Except for today, it seemed. 

Today, in this moment, I was facing a crisis of morals. My eyes were fixated on my sister's open laptop, the screensaver bouncing gently, unsuspectingly, innocently. Ryuuko had remembered in a flurry of curse words that she had fixed plans with her friend Mako for that evening, and bolted from the house. Once again, our father was out of town on business, and when she left, she took all of the energetic joy the house contained. Although, as of late, it has become rather stressed between us. 

We were not fighting. Of this, I am sure. My sincerity in this is assured simply due to the fact that I have already asked my sister. Her reassurance was well meant, but even more confusing. Her confusion was not sincere, and a strange, heavy emotion lingered in her eyes. Pain? Guilt? It was a strange expression, a sort of begging I didn't know how to address. Still, if Ryuuko did not want to confide in me about something, it was only respectful to agree with her wishes. I tried desperately not to be hurt by her secrecy, and altogether cannot claim I was successful. 

Without preamble, the only shift in our relationship has been in our sex life. For a few weeks, I battled with myself, questioning my levels of selfishness. Just because Ryuuko did not want to have sex doesn't necessarily mean she is falling out of love with me, right? On the contrary, Ryuuko has never been more lively in her willingness to please me with no discernible need to return the favor. 

It had been weeks, and all I could do was stew in the tension we had created for ourselves. Me, wanting badly to communicate, but wanting more to ensure my sister's boundaries were respected. I grit my teeth, my jaw flexing as I stared at her unattended computer. My heart was beating heavily in my chest, aching to confirm or deny the greatest fear lingering in my mind - Ryuuko was seeing someone else, and loved me too much to end things. 

Even the thought closed my throat. 

As I had watched her peaceful face sleep one night, I had conjured the idea out of pure fear and insecurity, my mind too rational to not realize this. But the logical wavelengths ever so insidiously started to sync with the illogical emotions. It was entirely possible. The signs and symptoms were present and accounted for: Her physical and emotional distance, her guilt, her extended periods of absence locked away in her room, her only companion her computer, and her overwhelming enthusiasm in seeing my needs met. 

My fingers itched and I swallowed harshly. 

The only reason I had to doubt the signals was my trust and security in that my sister loved me. I should trust that. I should. But my mind saw a picture of the last time Ryuuko had orgasmed around me, her face, her voice, and I remembered how long ago it had been. 

I had to know why. 

I had entered her room to deposit some of her laundry on her bed, and spotted her computer. I now found myself sitting, one leg folded on the bed, another still touching the ground. I tapped the computer awake, and drew a breath. 

At first, I didn't know what I was looking for. Reading her messages was simply too much, and out of the question.

My eyes tracked to the applications lining the bottom of the screen, and which were activated. One was bouncing, apparently needing some sort of attention. I scrolled and tapped on it. A black screen appeared, with a smaller window asking if the user would like to save changes made to a video. I frowned and clicked the 'yes'. When it cleared, I curiously found the 'play' arrow that had appeared. 

And my mouth dropped open in shock. 

As if on reflex, I exited the screen and closed the computer. My breathing was labored, and I felt hot all of a sudden. This is what Ryuuko had been up to? 

I stared at the screen, and my mind, working overtime in where to begin, only now registered the large photograph she had apparently set as her background. It was a favorite of mine, but she had always scowled and grumbled when introduced to it. On a raining afternoon after school, I had taken to cooking dinner and cleaning. As was appropriate for such activities, I wore an apron to protect my clothing. One of the rare days I wore the school's skirt and heels instead of the pants. The next thing I knew, Ryuuko had circled her arms around me from behind and hidden herself between my shoulder blades, nuzzling gently. I had picked up my phone from where it lay and reversed the camera to try and take a picture of her position, accidentally angling to include myself. In the photo, one could observe the gentlest of smiles on my face, and the blushing tips of Ryuuko's ears. 

My sister wasn't cheating on me. It was impossible. Truly. I loved her, and she loved me, and all of this could be sorted out through communication. I set my jaw. I trusted her fully, and it wasn't fair to be as insecure in our relationship as I had been. I breathed deeply and settled my shaking hand on the computer pad once more. Time to figure out what in the hell was going on with my sister. 

I found the video application and squinted at her viewed history. The first was a file titled, "Movie - Edited" and the contents of which, I was aware of. A brief picture of myself, abs flexing and sweating, flashed through my mind. The second video was named "Happy Bday Sats", and the third "Test 4 - Unedited". I flexed my jaw, thinking. With my stomach roiling, I clicked on the third file. 

The screen opened full view and started to play. Ryuuko leaned away from the camera, just having turned it on. She backed away from the camera, and was gloriously naked. I felt arousal flutter in the pit of my stomach, only to be multiplied ten fold when she circled her bed and placed a towel, her computer, a bottle of some clear liquid, and a red dildo on it. I swallowed. Ryuuko moved about methodically, and without preamble, started playing the video of us, got onto all fours and started to spread lube on the sex toy. I bit my lip, trying not to let jealousy flare in my mind, knowing where the dildo was going. 

But I felt my eyes go round with shock as I was proven wrong. Ryuuko seemed to breathe deeply, her eyes fixed on the moaning coming from her computer. She chanced a look at the camera, and muttered to herself, "Happy Birthday, babe," before turning to lower herself, spread in front of the camera. I felt my mouth dry out. Her right hand reached backwards with the sex toy and prodded around some. Just when I was about to mentally note that her aim seemed to be off, she lowered her head to rest on a fist, and slipped the tip of the dildo into the rosebud of her butt. My throat caught. 

My mouth dropped open as Ryuuko's recorded voice sounded out as she slowly slipped more and more of the toy inside of her. It was my name. 

"Sats," she whined breathily. I couldn't see her face, but every muscle in her back stood out in flexed tension, and her toes were curled on the mattress. She grunted as the base of the dildo touched her, and awe overtook me as she audibly sighed at the pulling stroke. 

I paused the video, my heart thumping. This is what she had been doing. My mind whirred at an incredible speed as the pieces all came together. Why she hadn't been interested in sex, her disappearances, her eagerness to attend to me, and the guilt she accidentally expressed around me. I barely noticed it before, by my erection was straining my jeans, and I was incredibly thirsty. She had probably meant this to be my birthday present, I realized dully. It didn't matter though. My birthday was still a week away. I could not wait a week to take my beautiful, wonderful, perfect sister. 

I felt my face flame. Now. I had to have her now. 

Before I could collect my thoughts, I was on my feet, making my way to the garage. I gathered my phone and keys on the way, and tried to think straight. My dick still pounding in time with my heart, I opened the garage and tried to plan. Difficult, when all I could see when I blinked was the fantastic image of my sister, naked, sweating, and moaning in my arms. I grit my teeth and growled, my eyes flashing open. I started the engine of the car and backed out in a hurry. I was half way down the street before I opened my phone and dialed my sister's phone number. 

The roar of the car's engine soothed me some, but the tones of Ryuuko's answer machine did not. I was starting to get angry, the reason for the reaction too far beyond my mind to calculate. A red light had me braking aggressively, and I dialed Mako instead. I clenched my teeth and tried not to picture the perfection of my sister's lips, wrapped around my own, wrapped around my breasts, around my dick- 

"Hullo??"

"Mako," I shorted out, not in the mood to play games with the usually unusual brunette. 

"Yo! Satsuki-sama!"

My spine gave a shudder as the husky echo of my sister sounded in my mind, the same name Mako addressed me with, but entirely different. Begging, pleading. 

"Mako, I need Ryuuko. Something.. came up. I'm on my way to pick her up from your house right now,"

"Ohhh," Mako sounded amazed. "Roger that! She's just laying on the couch right now. Feel free to take her!"

My brain dirtied her invitation in a millisecond, but I forced myself to relax. "Thank you," I replied, and hung up. With nothing to distract my mind, I focused on the facts I could conjure. Mako's home was 30 minutes away. Currently, I was 15 minutes into my trip, but my foot was edging the gas pedal closer and closer to the floor. I breathed through my nose and tried to quell my rising need to grip and scream at something. 

Once I got to Mako's house-

Well. Then, what? I blinked and ground my teeth. I would take Ryuuko. In the car. I smiled grimly, devilishly, to no one but myself. I so had missed making love to Ryuuko. Making her gasp my name, her violent tremors wrapping around me and sinking into my bones as she came down from her high. My heart ached at the thought. Still, I tapped my fingers on the wheel impatiently. And my once-brilliant mind finally engaged to remind me of the one thing that could darken my brow. I almost cursed, my sister's prolific vocabulary dancing in my mind. 

I pulled the car off at convenience store closest to Mako's house, and smoothly parked. I fixed myself before exiting the car, and took long, fluid strides inside the store. My walk could only be called a prowl as I found the correct aisle I hunted for. I frowned, pausing. Ryuuko had always been the one to find and purchase condoms, my aversion to them evident. I was surprised at the sheer number of brands and varieties offered. I squinted and chose two, comparing them side by side, considering. As I read, I noticed a teenage boy enter the aisle and glance nervously at the wall of condoms, to me, and to the floor. He fidgeted and appeared to be sweating. I tried to suppress a derisive snort. I settled on one and left the aisle, but halted a few steps away. A picture seared it's way through my mind, and I back pedaled to retrieve a box of lubricant gel. 

My intermission in the aisle seemed like some sort of pause in time, and stepping back into the parking lot whipped my mind and body back into the frenzied rush of moments ago. Impatiently, I tore out of the lot and back to the road. One handed, I tore open the boxes and counted the houses that passed by me. Finally, I found the right one and parked in the street roughly. I threw the door open and exited the vehicle. Vaguely, my mind registered that I had accidentally brought the condoms and lube with me, and I quickly pocketed the items. 

My lack of self-control and discipline should have embarrassed me, but the front door opened and Mako's brown eyes were looking up at me with excited expectation, and my jaw locked, hoping the arousal in my stomach would bubble down. 

"Satsuki-sama!" She crowed in her particular way, "My family is gone! Would you like to come in??"

As she spoke, my sister appeared over her shoulder, curiosity written on her face. The simplicity of her movements, the innocence in her eyes, the way her jeans hugged the v of her slim hips, I drank it all in. I breathed my sister in from a distance, and once she met my eyes, her face changed in the span of three heartbeats. Her eyebrows climbed, shocked, and then her supple mouth parted in shock as the same eyes I had, glanced down at my crotch of my jeans. I visibly twitched. 

The unnatural movement reminded me of my surroundings. I shifted my glance to the small girl next to Ryuuko, "Mako," I addressed. To my embarrassment, my voice was soft and hoarse, and Ryuuko's face flamed because of it, her expression twisting in confusion and frustration. My jeans tightened at what had just happened. My mind, so stuttering and halting in every line of helpful thought, managed to register that Ryuuko wasn't aware that the emotion she had just felt was jealousy. 

"No worries, Satsuki-sama!" the excitable girl all but shouted. She whipped a ridiculous salute at me, and took on a face so serious, it was near comical, "I need to find out where my family went to for the week. They forgot to tell me!" Her odd haircut brushed my elbow as she ran past me, and continued down her own street. I frowned after the girl. 

"N-Nee-san?" I whipped my head back around to face my confused sister, her expression hesitant and slightly vulnerable, "What's going on?"

I didn't wait another second. I stepped forward with an incredible amount of purpose, and crushed her lips to mine. The door slammed behind me, and my back felt cold as I ripped my shirt from my body, arms winding around Ryuuko and jerking her up and against me. She stepped backwards to avoid losing her balance, but her hands were in my hair, not allowing me to abandon my dominant role. I growled, her body under my hands, her fragile and feminine figure so pliable and soft. But her clothes irritated me. Frustrated me. 

I pulled my lips away, and stared into her dilated eyes, my hands going to the front of her jeans. Whatever she saw in my eyes was hers to keep, and she gasped at the sight of it. I made violent jerks at her pants, the button and zipper disassembled in moments. She glanced down at my work and her breathing picked up. My hands brushed against her already swelling erection, but paid it no attention, even when a whine slipped past her teeth. I ripped her jeans and underwear down in one go, and dug into my own pocket. 

She gasped as I produced a condom and unzipped my jeans. My penis slapped against my abdominals, and I quickly ripped the foil open and rolled the rubber over my dick. I impatiently glanced at my sister, her eyes were dazed, her lips swollen. One last, lingering kiss, and she whimpered into my mouth. I gasped away from her, and she shifted backwards to rise and seat herself on the back of a couch I hadn't noticed she backed herself into. 

I stroked my dick, and her legs wrapped around me, my hips slotting perfectly in between her thighs. She moaned as I ran my penis through her folds, and the warm slip felt so good, I lost the last thread of my patience. I positioned my head at the softest spot of Ryuuko, and her soft hands slipped around my shoulders. 

"I love you," she whispered, kissing my neck. I shuddered, and closed the distance between us, jogging my hips forward. 

Simultaneously, we groaned. Ryuuko was so warm inside. So soft and wet, hugging me snugly. I felt the spasming of her walls stretching to remember me. She shook in my arms, and I hummed deeply in my chest. I withdrew and drove forward, setting a pace so comfortable, pressure immediately began to build behind the base of my dick. Ryuuko felt so incredible. She felt like home. I held her tightly in my arms, as she made these amazing, breathlessly joyful mewling noises of needs being satisfied. 

It felt so good. The sex was amazing, most obviously. The tactile feeling of being inside her tightness, pistoning in and out of her with bruising force, and Ryuuko's desperation breathing against me. It was intoxicating. But the whispers of love I wove into her hair had her scratching at my back. Her vagina fluttered lovingly around my dick, and the wet sounds of our joining was absolute song. She thrashed against me, and I held her steady, only love and deep amounts of trust flowing between us. I grunted with exertion, my balls tightening. 

Without preamble, Ryuuko's body tightened against me, and her heels dug into the back of my legs as she came around me. I gave a great shudder as I let myself relax, and I slammed my hips as deeply as I could and ground against my sister wantonly. Ryuuko gave a small scream as she came a second time, and I spilled into the condom. She chanted my name softly, her hips rolling, and my mind cleared enough to note that she was looking for the warm fullness of my cum inside of her. I felt my heart warm from her unconscious search for the feeling. 

Her body softened against me, and I made to withdraw from inside her. Ryuuko's legs tightened by a fraction and she grunted lightly. I smiled and hummed soothing sounds for my sister, her fingers working through my scalp contentedly, kisses pressed to my shoulder lazily. I sighed after a moment and gathered my strength, circling under Ryuuko gently and lifting her up.

She rightened against me, and placed a loving kiss on my mouth. I hummed into the kiss. Her vagina gave another spasm and I realized I was still hard. Ryuuko practically purred and smiled against me. She pulled away and smoothed through my hair. Her eyes were rimmed with want, and she spoke with sex in her low tones. 

"Spare bedroom down the hall, first door on the right," 

I nodded and moved. She rid herself of her shirt as I walked, and I kissed everywhere I could reach. I opened the door she directed me too, and my heart leapt as I remembered the reason I had flown over here. The bed creaked as I set her on her back and crawled on top of my sister. She caressed my face and I smiled down at her. 

"Ryuuko," I breathed, just to feel her name as well as her body. My sister smiled back and craned up to kiss me once more. I pulled a deep breath through my nose and separated from her. I kissed her forehead, "Do you trust me?" Her answer was an immediate nod and deeply hummed confirmation. I placed another kiss on her lips and pushed off the bed to stand. She watched me from the bed as I pulled another condom from the pocket of my open jeans, and the bottle of lube. Her breathing picked up as I locked eyes with her and shimmied out of the rest of my clothes and took my bra off. 

My eyes held hers seriously, "Turn over,"

My sister hesitated, and I watched a vulnerable emotion flicker through her eyes, "Satsuki, I-" she broke, and I watched her while I moved, the latex of the condom unusually loud in her silence.

"I want you," she bit her lip adorably, "Somewhere else," she whispered, something akin to fear in her tone.

I only adjusted the condom calmly, not surprised in the least, "I know," I replied, "Turn over."

Ryuuko blanched, her mouth dropping open before following my instructions on autopilot. When she realized what she had done on instinct, she rose to all fours, and then looked to me. Her last request came in the form of her reaching her hand out, and resting it over my own on my dick. I raised an eyebrow. 

"Take it off?" she begged lightly. I stared. And ripped the condom off. My sister seemed to chuckle at me for that, but hid her face in the sheets. I wrinkled my nose at her and joined her on the bed, resting on my knees behind her. I opened the bottle of lubricant and applied some to my hand, stroking my dick with it. I tried not to shudder at the building it put behind my penis, and reveled in the pride I felt at my length. I poured more on my hand and spread my sister's firm cheeks. Gently, I started to massage the tight bud of her cute ass with my wet fingers. I was guessing at the rhythm she liked, but when her sigh turned into a slight moan, I knew I was on the right track. 

I took a small breath and slipped my index finger inside, the ring of muscles giving with ease. My sister gave a slight push against me, and I understood: she had been training for my sake. So that I didn't have to build her up this way. Another push against me, and I withdrew from her. I hushed my sister gently and poured more lubricant on her ass and my dick. Though she had prepared for this, I had not. I still was a little afraid of hurting my beloved sister. 

I placed my dripping and bare cock at the entrance of her ass, and pushed. It was a lot more pressure than I had ever had to exert to enter my sister, and I felt odd at the force. Finally, her ass opened and the head of my cock was swallowed. I felt my head spin. She was so tight. I immediately wanted to start fucking into Ryuuko, and have her ass choke my cock until I exploded deep within her, but I halted. My sister was moaning, the rigid muscles of her sphincter flexing around my girth, and she had reached backwards to place a slim hand on the column of my thigh to still me. 

"Ryuuko?" 

"You're thicker than-" she cut herself off abruptly, "You're so thick, Sats," 

I inwardly purred with satisfaction. I was bigger than the sex toy she had been using. By a considerable amount, if this was anything to go by. My sister twitched and paused, and I used the moment to reach underneath her and stroke her tight dick. "Nee-san!"

I gave an instinctive jerk of my hips, the name digging into my mind and feeding my ego. It was wrong, I know, but what else mattered? I was in the middle of having anal sex with my sister in a stranger's home, what did it matter if she recognized me as her sister? 

"Imouto," I rumbled, and I watched as Ryuuko's shoulders twitched, "My darling, I want to fuck you," I leaned and kissed her back, pulling and pushing the tip of my cock back inside of her sphincter. She shuddered, and an idea formed in my mind. "I want to fuck you, Imouto. I want to treat you like you exist for my cock, and only my cock," 

The effect was instantaneous. My sister's ass gave a fantastic spasm, and she gasped, shuddering, "Nee-san. Nee-san, do that again! Ah, fuck! Move, nee-san. Fuck me," she begged. 

I smiled softly, releasing her cock and grabbing her hips. Her ass was so tight. I pushed, and kept pushing, "Do you like this, baby? Do you like it when your sister is inside you? Hm?" I was fully sheathed in her ass, and my sister was panting heavily. I slowly pulled back. "Mm. Ryuuko, your ass is so good, my love. We're not leaving here until I fill your ass with my cum, Imouto. Not until you scream my name," I picked up my pace to a measured jog, and the pressure around my dick was nearly choking, "You love the way I fuck you. You love every moment that I break you with my cock. Because you love my cock, don't you? Mmm?" I stilled, and Ryuuko nearly cried, "Don't you?" I tried again?

"Yes!" My sister shouted, sounding near tears, "I love your cock, Nee-sama!" 

I flipped my sister over, and pushed to raise her legs over my hips, one over my shoulder, leaning into my pounding thrusts. I flexed my ass, abs, and arms to properly dig into the friction that felt so good. It was intoxicating, to look down and see my sister's innocent ass stretched open and tight around my large dick, her vagina wet, weeping, and sadly empty. I threw my head back and simply felt the sensations, my hand lifting from the bed to grasp Ryuuko's dick and stroke in time with my thrusts. 

Her groans and growls turned a higher pitch, and I would have smirked if it weren't for the fact that I was desperately trying not to come. My sister's leg spasmed over my shoulder, and I felt her spill in my hand.

I couldn't help myself, Ryuuko just felt too good. I gave a great, earth moving shudder and my entire body flexed as my orgasm rolled from the base of my skull to my hips, exploding out of my through my cock. I felt my cum shoot into my little sister, and her reaction was a hum. I collapsed on top of her, breathing heavily, my nose in the joint of her shoulder and neck. 

She took her turn rumbling at me, and the vibrations of her chest soothed me into closing my eyes. My body languidly pushed into her ass as a reassurance, and my sister yelped and laughed.

"Satsuki?" 

I hummed in askance. 

"I love you," 

I smiled into her neck.


End file.
